Anyone remember playing Final Fantasy XII? Wasn't my favorite of the games, but I really liked the Gambit system they introduced. It gave the user some control over how the AI teammates reacted in battle. You could program a prioritized list of actions to take, and a conditional threshold for when to perform the actions.
I think it would be neat to incorporate something similar into your arena squad, so that each user could have some degree of control over how their team plays defense in a match, instead of relying on the (fairly stupid) AI attacks.
Seems silly, for instance, that treya teams have no problem beating Revan in offense, but they get smoked by the same opponent when defending. Imagine if you could program isolate and fracture to always Target Revan and Yoda when defending, or save Jolee's revive ability for when an ally has died, or if a specific ally is nearly dead. Or only use GK's cleanse when the party has X debuffs etc...
The devs wouldn't need to bother hardcoding specific abilities, and at the very least would add some variety to battles nowadays.