Second recommendation is what I call "Replay mode". Where after the match the battlemap comes up and players could opt to watch how the battle unfolded. The replay could be sped up by x2 or x3. Chat would be open so that players could comment on what happen, what went right and what went wrong.
I play chess and almost always after a game the players go over it and comment on what they thought they did right or what they could have done better. The weaker players benefit by getting insights on what stronger players are thinking about during a game. It also adds to the immersion factor in that they replace their old thinking and start thinking better.
Hopefully this will help players with the learning curve and reduce the whining we see so much of.