Maybe the issue of those rules targetted at ff characters should be walked around.. I remember the rules mentioning that if this becomes a problem that ff characters will just be removed.

Anyways kind of an addition to what K_A has already said
Don't you think that Cloud would stock up on items prior to going up against X? Being completely prepared? But he is not allowed to.
Then why would X be allowed to stock up on energy gained from items prior to battle?