Finally beat FF1 with only White Mages (no class change). Turns out this wasn't all that difficult. Once you make it past Astos, the rest of the game is not that much of a problem. It's the early part that's a challenge where all you can do is cast RUSE on yourself and slowly plink away at enemies with 1-2 HP of damage done to them.

I would do a solo run next, but I looked into it and it basically amounts to cheating to win the game? You have to abuse the peninsula northeast of Pravoka, and you have to save scum to abuse the stat gaining during level ups otherwise you have no chance of beating the final dungeon. If that's what it takes then what's the point? Maybe a solo Knight can beat the game the honest way, so I might try that.