It is painful to level this squad when your bomber has no rear gunners or upgrades. Let us use p47 so it will be easier. This would also allow you to use p47 with american squad instead of the british attacker 2. Other factions top attacker planes can be used on attacker 3 squad so why not usa?
I already had this squad maxed out like within a week since it was added.
Was fun and not very difficult.
Using the P-47 to upgrade the B-25 squad seems too easy to me, sorry.