It feels like that's the only way to win, if there even is an exploit.
The fact that she's the final boss, of sorts, of Triple Triad and you can't choose your cards or where to place them is god awful game design. As is Random. Why have a card game about collecting to make your deck better, only to have the best of the best NPCs have a rule that leaves the game entirely to chance?
Anywho, any exploits would be awesome. Getting 1/2/3* cards consistently against two 5*, one 4* is a win-less endeavor.