Do you know how deep the water will have to be for that thing to get immersed on his particular rig?

And the fact that he's not really a mudder (but some mud if fun). With some custom skids and rubber fender guards (like the 1st genners have) that thing will probably outlive his first set of axle shafts.

Even with the tires he's running, not being a throttle jockey will help him out a ton. I've heard of the guys that bust everything up running anything over 33's on their rigs. But I also see a lot of throttle out those guys, and not a bit of finesse. Wheel spin won't always get you over the big stuff/hard line. And wheel spin is the biggest cause of that snapping sound.

If he starts breaking stuff, I'll be really suprised.

But upgrading the MC might not be a bad choice either. That'll take some work though, and might take until the summer time to accomplish. Shouldn't be hard to locate one, and perhaps a manually adjustable proportioning valve to boot.