I have no problems with grinding, really. But here in this game it’s complicated: you have to grind 4 campaigns separately. I know, they are different nations and stuff… but there should be solution, they should share at least CAMPAIGN level only. I’m not talking about squads and weapons and all other things… PLEASE make campaign level shared in all 4 of them. took me 1 full day to get from 8 to 9 level, and XP required is getting even higher and higher…
Now you keep people attached on single campaign cause of that. I don’t want to switch now and start from 0… will unlock gunner in next level, will have assaults and gunners in each squad… If I switch, I have to run with 1 bullet sticks again 
2 of my friends already left the game cause of that… Please devs think about it, Shared campaign level will not hurt this game.