Lyn, Lucius and Canas are Mid Tier, Dorcas is High tier, Rath is Mid-Low a-
Oh, wait, that's what I'm not supposed to do. :D
But to be serious for one moment, in FE7 if you're moderately clever you can use most units. If you're pretty clever you can use even the worst units. :D
Also, sandman, have you played FEDS? Sounds like you'd love HM5. Just to give you an idea what it's like, most enemies have higher stats than your units. High defense, or attacking indirectly makes units epic.
ie. Archers are way more awesome. So are Knights. :D And Strategy.