Let me help. I've personally ran the ESC's and motors in 1/10's with 540's and 2s!

1st, let me ask what Hobbywing ESC you have. Ive ran the 120A SC8 on 2s & 4s in 1/8 and 1/10. It worked flawlessly! Now if its a XErun 80A it doesnt respond well with 2s. Hobbywing tech support advised against it *unless your running a external BEC. In which case its a great set up with a bec installed.
Theres really no overkill in ESC's. The motor draws whats it needs from the ESC. The ESC draws what it needs from the battery.