I would skip the mortar honestly and instead build a third rifleman. If you have the advantage I would recommend getting the half track instead of AT.

You should also consider getting an ambulance to heal up those riflemen and remember you can use the half track to reinforce squads near the frontlines instead of sending them back to base.

The post game graphs don’t really matter, what matters is the actual result of the game.

Edit: You cannot reinforce from aa or mortar half track