Alright. My two cents here. :twocents:

Does all that really matter?
Yes.
It's ff2j.
NES version? Origins? Dawn of Souls? We know it's FF2j, this is the forum for it.

Look, I give Guy and Frionel the best armor I can get. Heavy, I guess.
The heaviest armor is not by default the best armor. Often the opposite is true. Defense is nowhere near as important as evasion.

(ThisI also don't understand. OBVIOUSLY, Guy gets hit FAR FAR more often than Frionel. And the 4th member gets hit more than Frionel too.I mean, Frionel's at the front, what the heck?)
The fact that Firion is first in the lineup has no effect on how often he gets hit. To be honest, I'm not sure how they figure it, but this isn't like FFI where the formation determines the probability of being attacked. It wouldn't make sense that way if you think about it.

As for the rest, there are others who can explain the mechanics of the game far better than I can.