I've been messing around in the Arena for a while– I never checked the forums so I didn't realize there was an official guide that functioned better than the in-game tutorial– and it took me a while to learn exactly how the game worked.
One thing that would've helped me is varying the ability icons more. When I looked at those, I figured the synergies were more important, because all the ability icons looked the same. It'd be nice if I could tell at a glance what creatures have what abilities, instead of having to hover over everything every single time.