when you play with an AI tammate look at the numbers after the game. Compare munitions (unless youre brit with that upgrade) that is, count 1/100 of your total income, then use your ally´s total number (divide by your 1% number) to get the percentage. Your manpower upkeep will be different so you cant compare it.
I posted in in another thread as well and manpower and munitions bonus on hard are 150%, while on expert it looked like 180 or so
so no 125 and 150. 150 is on hard already