Grinding??
I'm not sure why there are so many complaints about this. I personally thought there's was more grinding in the earlier games, even though I did enjoy them as thoroughly as this one.
I think it's about getting your core strategy right but also being very flexible if needed, depending on what map you're on. If you seem to be endlessly grinding then it's something YOU are doing wrong, not the game.
Congrats on creating yet another great game. It keeps me coming back for more!