In my opinion the grind was just playing the game, you got XP and stubs for whatever mode you played in and I liked that!
I think using March to October for stat grinds makes sense.
Personally I found in 2018 you had to make a decision to either play the game or grind first inning on coors and I just didn’t find that to be fun. I would prefer to play the game vs the computer rather then get 3 doubles with a silver 2b in a game.
If they added stat grinds such as innings pitched in any mode or games played in okay with that.
Also moments are just glorified stat grinds really, take player X do task with said player. The grinds were there people just didn’t do them since there was better/ different ways to rank up and get rewards