I've always liked this game. I just wish it had more content, both playable CO-wise (why is The Beast not playable despite having his own theme?) and game mode-wise. Design Maps was a huge step-up from the one in the Wars World versions, but no Hard Campaign sucks. Trial Maps just weren't it either, as some were either incredibly short or old multiplayer maps from the earlier games (one of the, if not the, worst multiplayer maps,
Tatter River, is a Trial Map). You also can't choose your own CO in Trial Maps if you want a rank too.
Gameplay-wise the COs are too different from the Wars World COs that I think combining them in the same game, even if it's just in a mode, wouldn't really work. Although I guess they could always change/retcon the abilities from one generation of COs to make their abilities match the other generation.