I doubt anyone would argue that Troy is one of if not the best overall character in the game. He joins in the Prologue and comes out swinging with solid bases and Multichance. Earlygame Troy will be an invaluable asset to your team and although late game he will fall of a bit due to Knights having relatively low stat caps, he still can more then pull his own in the lategame.
The only one who can truely contest with Troy is none other then Merida. She joins a little later at Chapter 2 but comes with her personal weapon Dandelion. Although she doesn't come with Multichance like Troy she instead comes with Lightfoot which is an invaluable skill that bumps her MOB up to 9, making her incredibly fast at getting around the map. Her low base STR can be an issue early on but once she starts rolling she can become quite the boss killing machine.
Eddard is the last joining character in the game(other then the replacement units if he dies) and normally I'd be like well he missed 90% of the game so can't really call him good. But in those last few chapters he is so impactful and from a pure who's the strongest unit standpoint, he easily takes the cake. Very high bases, 8 MOB, good skills, the Dragonlance and high growth rates, whats not to love in this man?
Although she comes a little late, a dancer is a dancer.
Zade is a suprisingly competent main lord, his bases are solid, good growthrates and has good skills.
He starts with 6 MOB which is not bad for a unpromoted unit and then increases to 8 upon promotion to Archliege, allowing him to traverse the late game maps with ease. He has two personal weapons Edelstern and Emmung, Edelstern acts as a brave sword and allows him to one round nearly anything early game, and then Emmung although missing out on the brave effect has a whopping 15 ATK, 120 ACC and 50 Crit aswell as being immune to attack nullification. His only real downsides is his lack of 1-2 range from being locked to swords, a late promotion coming in at the end of Chapter 15 and being one of main lords he often has a place to be and will have to leave the fighting to the others.
Theodel & Accorte
Theodel and Accorte are about on equal footing, arguements can be made for either one being better. Theodel joins Chapter 3, Accorte won't join till Chapter 7 but she joins with her personal weapon Nashorne, Theodel won't get his own personal tome till Chapter 14 and is less useful then Nashorne. Both have similar bases and growths, Theodel gets divine magic, Accorte gets dark magic, dark magic being the better of the two but Theodel has better personal skills. Both of them fill a similar role and I usually find myself fielding only one of the two due not being able to buy a second Holy Vestements only Chapter15x. Although they are both solid units and theres nothing wrong with using both.
Stat-wise Haldyn is a stronger Zade, similar growthrates, superior bases and a better set of skills. Where he loses out though is his lack of a personal weapon and his 5 MOB which only goes up to 6 upon promotion leaving him in the dust with the rest of the unmounted rabble. Also just like Zade he's sword locked but he at least he has access to greatswords aswell.
1-2 range, 8 MOB, that's all you really need to know. If Urven joined earlier he would be an easy S-tier, he functions similarly to Merida and Troy with one main exception: HE HAS ACCESS TO 1-2 RANGE BEFORE PROMOTION. He has solid bases, decent growths and Dispel Effects patches up his weakness to horseslaying weapon. Similarly to Troy he'll fall off in the late game a bit due to his low caps and lack of personal weapon but he'll be still able to pull his own.
Dune leaves a poor first impression on most people due to him starting with a hunting bow that slows his speed down to a measly 2 at base but as soon as you get him a lighter bow he can really start rolling. Dune comes with good bases, good growths, Multichance at lvl 16 & Critical Edge on promotion and at the end of chapter 9 can get his personal bow Bow of Aragoth which is incredibly potent at shooting down dragons and confers to him the ability to canto.
Hilda joins on the late side but is no slouch with solid bases and growth rates that are overall better then the fighter bros. But that's not what puts her in A tier, her skill Critical Reprisal(which is just Wrath but guaranteed Crit as opposed to 25%) is an incredibly strong ability combined with her stellar personal weapon Justitia she becomes an enemy phase juggernaut.
When Lilia joins in Chapter 6 its time to get forget about that wench Athol, Lilia is leagues more useful then her. She comes with the herb forager skill which that alone makes her worth deploying as she will save you a fortune on healing items, then she comes with debatably the best skill in the game Industry. Unlike a certain useless healer, Lilia can promote into High Priestess and gains access to Divine magic, making her the only combat unit with the Industry skill other then Ma'aya.
Haven't fully formed my opinion on Slayne yet, he's one of the most subject to change on this tier list but he comes with decent bases and good growths and surprisingly the highest STR growth in the game at 45%. His skills are good and although he doesn't have any personal weapons he may as well as he is the only unit capable of using Ballistas. This utility can prove very useful for breaking stalemates and taking out hard to reach siege tomes and ballistas.
Cyltan has good bases and decent growth rates, he has a lack of combat skills but Lightfoot gives him some great maneuverability and Commander which is always useful. His personal weapon Am Solim is fairly good but is outshined in nearly every aspect by Dune's personal weapon. Overall Cyltan is a less powerful Dune that joins later but has the advantage of his superior maneuverability which is not to be underestimated.
Zayid is a powerhouse when you get him and If you choose his personal weapon Agza's Crescent becomes quite the force to be reckoned with. His bases are good but his low growths can impact him in the late game, causing him to have frequent hit issues and he struggles to one round.
Decent bases and growths but he comes with his personal weapon Halidole which is a solid tome and personal staff Formalinthe which is very useful buffing tool combined with his Battle Hymn skill. Siegfried makes an excellent utility unit but still has competent enough magic to remove any threats that he needs to erase.
Bonacel is an incredibly useful wall for the first half of the game, you can throw this man into nearly anything and he'll walk away relatively unscathed. His growths aren't even that bad with 40%STR&DEF growth which is all he really wants anyways. Although Prody has superior growths, by the time he catches up with Bonacel it'll be mid-game and guardians are about at the end of their usefulness then. The larger maps and more abundant mages of late game will leave the 4 MOB boys either in the dust or fried alive in their armour.
Prody essentially does everything Bonacel does but worse. As guardians go they're strongest in the early game and just get worse and worse as the game progresses as maps get bigger and mages become more abundant. In the rare chance Prody sees promotion you'll be dissapointed to see that he gains no MOB unlike most foot-locked classes.
His low AGI combined with being axelocked means he gets doubled by most foes but he works as a serviceable filler unit late game.
Athol's lack of promotion really dampens what could have been a great unit. She has a high magic growth rate but with no offensive magic to speak of its relatively wasted. She's force deployed in many chapters so you may aswell use her if you've got her but if you have the choice between her and Lilia I'd usually pick Lilia. She also has an interaction with Cezar where once a map if you're funds are under 3000d Cezar will give her Cezar's Lucre if they're standing beside eachother.
A good unit when she joins you in Chapter 5 but then leaves until the final chapter, which she's serviceable in but will be outclassed by most of your units by this point.
A good utility unit for the maps he's available you should replace Cezar with him. He's a lockpick with the added benefit of repairing your other units personal weapons.
If you train the hell out of her the chapter you recruit her and promote her into a Dragon Knight she CAN become a good unit but this requires alot of investment just to get decent unit. The most common actual use for her is just being a shopbot, due to her Master Haggler skill giving her a 33% discount at shops.
He picks locks in the early game and gives Athol money. Training him for combat is relatively fruitless due to his 5% STR growth and 3 STR cap, just stick to lockpicking.
A mounted healer that can use bows aswell should theoretically be good but her base 3 proficiency prevents her from using any good bows and this late in the game you don't want to be leveling someone just so they can use a half decent weapon. Her 7 MOB staff utility can be nice though.
By all accounts she would be a decent healer... if she didn't leave permanently after Chapter 2. Just use her when necessary in Chapter 1&2.
Even if she didn't leave immediatly after the chapter you recruit her, she has 3 MOB, 3 FRIGGIN MOB. Bonacel and Prody run laps around this fat tub of lard.