I think that's one of the appeals of DOTA games, because you only control your toon you only have one thing to micro, you do have to macromanage in the wider game and your build.
On the subject of "cartoony" graphics, personally I find it depends on the game, DOTA2 vs
LOL is a good example here,
lol has a more cartoony look to it but at the same time that gives it a cleaner look making it a bit easier to see what's going on.
One thing I've found is that youtube is very handy for seeing what a game is like before I buy it.