I never played the first but the 2nd is one of my favorite Wii games. I love RTS games (even though I'm not too good at them), and I enjoy actually going down and getting dirty with the gameplay, so this game spoke to my soul.
In my fantasy world Wii U would have the 3rd game and we'd have something like 16 player battles where each team of 8 takes a battalion against one another. You're able to switch classes as you play, command troops in your area, and maybe even build barracks/factories to produce more units for your team.
It would have the same great offline campaign as it's predecessors as well.