'Look out. Here come Ginger Muffin Khan and his horde'
How about Magnus? Not quite as over the top as Maximus, and a fairly common first name in Sweden. We named our son Magnus (the name is rare, but not unheard of here in Germany), and so far we haven't had any problems.
Means Destruction in Latin.
Seriously, it doesn't matter what your kid's first name is, as long as their middle name is "Danger".
As long as he doesn't get called "minimus" by a girlfriend, "maxi-pad" in school, or "maxed-out" as an adult...
Anyway, if you want to one-up your friend (so you won't have two Maximi rasslin'), go for the name of somebody known for having kicked Roman ass: Arminius, or just Armin.
I wanted to name my son Anthony Danger.