Would my team beat 40 mihawk

Captain G3 luffy level 80
Arlong 4* level 72
Alvida 4* level 60
Hammer usopp max level
Mr 3 4* level 50

And a high level G3 luffy friend

Yeah that should be fine, I would replace the mr. 3 with another str as you don't really need the 6th turn and odds are he will get locked out on 4th stage as your combos are too low to take out more than 3 units..

My only other str is Mr 5 would he be better

If his attack (when doubled) is more than Mr. 3 than yeah. Plus his special will deal double damage to mihawk as well.