I disagree on learning the game with Ermor themes, as they play very differently from other nations. Both underwater nations are quite different in their troop and mage availability, and being underwater complicates things even more, so I wouldn't suggest them either.
I wouldn't advice on using SC at all when learning the game. (and much less without explanation of the term
) Super combatants are rather important in multiplayer, but I think using national troops against the AI is more interesting and challenging.