I'm more concerned about performance of your rig and braking, although I presume you'll be adding a supplemental brake system.
Again I'd ask about the coach weights. Actual weight when loaded for a trip, subtract from the gross combined vehicle weight rating, do you have at least 5k lbs left? Just because the hitch is rated for the load does not exempt us from the manufacturers GCVW rating.
Having towed a 4500lb Jeep Wrangler Unlimited with a gas coach I can tell you grades will be "interesting" with that much weight behind you.
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
Wrangler Unlimited toad