Desperation Attacks

So one aspect of Final Fantasy VI that is just about tossed aside is their Desperation Attack system. It's essentially the basis for the Limit Breaks seen in newer games, where a character at low HP has a chance to perform a powerful attack as a last resort, i.e. when they're at their Limit. But the problem with it in VI is that the chance of it coming is so low, it's generally just another form of a critical attack seen very rarely. So I was wondering, would there be any way to change the odds/chance of performing a Desperation Attack so that they happen more frequently? My hack is centered on a heavy storyline with great emphasis on each hero's character, and as such, having each character have their own Limit Break and having it actually happen often enough would add somewhat of a more unique feel to each character.