Don't know if it would tow any better as I have never towed with an Expedition. All I do know is that the Tundra should have no trouble with that trailer. My previous trailer was 7200 lbs loaded and current trailer is 9400 lbs loaded and I have not had any issues towing either trailer with the Tundra. IMO the Tundra is a very capable and solid tow vehicle.
My towing can be long distance too as we just got back from Florida with the 9400 lb Reflection and combo handled very well. Total distance was 4700 km or nearly 3000 miles.
PS the weights are measured at a CAT scale not an estimate just for information.