We have a 2010 GMC Acadia - twin to your Enclave. Tows four down with no problem. We have the Blue Ox tow bar/base plate, and use the SMI Air Force One braking system. Excellent combination.
I also installed the under hood switch to remove the 50A battery fuse from the circuit when towing. Saves having to manually remove the fuse and replace it. Pricey but worth it in the long run. You'll find it at rv-partsplus.com
Follow the owners manual and idle the engine for 5 minutes before towing, and for 5 minutes at every fuel stop. We do that about every 200 miles just to be safe, as well as for 5 minutes when we call it a day. Keeps the transmission lubricated.
Hope that helps!
Joe and Debbie, Emma the Aussie Cattle Dog who adopted us
2012 Discovery 36J, Blue Ox and Air Force One, 2010 GMC Acadia Toad
USAF (Ret) WDØM http://wd0m.com