Gameobject compare does not work here, as two different gameobject are always different even with same name and other properties. There are many ways how to achieve what you want,
-give these gameobjects same name, and then use "Get name" action and "String compare"
-put a FSM to these cards, and define Int variable that has same value in both cards. Then use "Int compare".
There might be more ways too, I probably would use the naming solution.