That is essentially the exact same mh as my Safari Simba except I had the 330 CAT engine and a couple more hundred torque. Still, I would bet that you have a 10,000 tow limit (towing capacity). I would also venture to guess that the 4000 lbs you speak of is the CCC (cargo carrying capacity) which is the difference between the GVWR and the curb weight).
You are good to go with your 5000 lb jeep.
Ron
PS... noticed I said 5000 lb jeep...meant 4000 lb. Also, even if your coach is NOT rated for 10,000 tow, it surely is rated for 5000 lbs.