Final Fantasy VI Advance - Perfect Playthrough

[Ebeneezer Goode]

The problem with that is I had to level Locke up to level 7 during the Mine Cart ride, before the banquet I've got a party of;

Terra - lv 6
Locke - lv 7
Sabin - lv 6
Edgar - lv 6
Cyan - lv 7
Gau - lv 7
Setzer - lv 6

I take Terra, Edgar, Sabin, and Setzer who all have about 384 exp to play with before next lv up. I'm not great with maths, but if one of them gains a level wouldn't that then be above 6.99, meaning Shadow joins at 7 instead of 6.

I'll try it out, but I think I'm screwed, was Locke only mean't to gain one level during the Mine Cart ride?

Edit: I'm about to leave the WoB now, and need to level Gau up for the fight with Air Force, but with the GBA version having a bonus Esper with HP +100 (Diablos), does this completely change how I can level up Gau and the rest?