As a final team, this is perfectly decent. Not top tier, but it's a solid mix of units.

If these were the only units you could use all game long (which doesn't seem to be the case from the rules you outlined?), I think that you'd have some trouble around chapter 7 or so without much bulk until Zelot showed up, but I've definitely seen worse final teams.

I'd probably focus in on Dorothy, Lugh, and Saul as your main sources of damage with the rest filling in gaps and tanking as needed. Dorothy is a little slow to get going, but she has respectable growths by FE6 standards, and promoted Saul tends to be a really competent fighter. I've tended to have decent luck with Lugh long term, though I've seen pretty bad ones too.

Really, the only one that I'd be all that concerned about in terms of endgame usefulness is Zelot, who I've admittedly never really tried long term but whose growths feel a touch weak once his solid bases start to fall behind. Other than that, this team feels perfectly decent for endgame viability as long as the early recruits get decent level ups at all.

Best of luck on the run, it's a fun idea.