Yes, that's correct. I have AWD and of course it's always on. The truck handles 5k lbs with no difficulties. Rock solid. I'd love greater towing capacity, but Honda would have to go V8. I don't see that happening unless they decide to go after the full-size market.
Number of cylinders has little to do with power in modern vehicles. Honda's own turbo 4 handily spanks their V6 in power/torque output, particularly at lower rpms.
Granted, there would be more stress on the turbo 4 vs the V6 when towing, but the turbo 4 will get there faster. If you're towing at max for a long duration, then the naturally-aspirated V6 would probably be better from a durability standpoint. This is why Ford does not offer the EcoBoost on their HD trucks.
All of that aside, rest assured that power is not the limiting factor in Honda's tow rating. If anything, it may be the likelihood of the transmission and/or iVTM-4 clutches to overheat when towing max loads in strenuous conditions.