I don't feel like Power Grid and Mage Wars feel that similar because in Power Grid the player out in front is at a considerable disadvantage, and you are trying to stay just behind the other players until you are able to swing ahead in the final round and win, whereas there is no reason not to press your advantage in Mage Wars. In Power Grid, The way that the player in the lead is at a disadvantage, and you don't actually want to press your advantage until the final round is the reason I don't like the game.
Normal Mage Wars Arena reminds me more of miniatures and real time strategy games than eurogames, though there is a fair amount of resource management, which is reminiscent of eurogames. The big difference is that eurogames don't generally feature as much direct conflict; you're usually trying to get a higher score rather than eliminate your opponent. Comparisons to eurogames are probably more apt for Domination than to regular Arena, but I haven't played Domination yet, so I don't know from personal experience. I think of Mage Wars as a turn based version of a real time strategy game crossed with a minitiatures game corssed with Magic, but that's based on Arena.
I think the comparison to Go makes sense because that comparison was based on the similarity in tempo rhythms between the two games, plus the conflict in Go is pretty direct, even if other aspects of the games are completely different. Unlike in Mage Wars, you probably can't completely eliminate your opponent from the board, but if you could, it would be the correct play.
Pixel Tactics has a somewhat similar feel to Mage Wars, though it's much more tactical and less strategic (and, at least for the first set, much more vicious).
Summoner Wars is the obvious comparison, though Mage Wars feels much more organic, and less stylized, since movement is more fluid. Summoner Wars always felt like a giant gridlock. Mage Wars is also much more strategic, whereas Summoner Wars is more tactical.