The mechanics look ok, but you should really focus on the graphics, otherwise you wont get many players. Hope development goes well, cheers!
I dont see how mobas could kill MMORTS, since those games can be complementary, for example Ogame and Dota can be played simultaneusly.
Only Age of Empire II, I didnt like the AOE 3 graphics, more a fan of 2d graphics over 3d in RTS