Right. It’s min(Deck Level, Caster Magic). If no deck, it will be L1.
I cannot remember any specific one, but every troop with ability “Turn target into card X” was like this. Maybe it was corrected later, I checked it long ago, and didn’t repeat.
I read you wrong first time. So for consistency you want to add special rule for case when collection doesn’t implemented. Specifically, Arena, because I don’t remember any other example. Right?