"Struggling" is obviously subjective, but how does the Tahoe struggle? Do you mean it downshifts a lot, or what don't you like about the Tahoe's towing performance? Maybe you can explain how you quantify struggling.
Just saying, all naturally aspirated v8 gassers are going to downshift a lot when towing, run at higher rpms, and so forth. The Armada, Expy, and others will downshift a lot as well. They have to -- none of them make very much power at low rmps.
I'd just hate to see someone buy a new TV with unreasonable expectations is all. If you want something that will tow the same as it goes unloaded, well, there probably isn't an option in the 1/2 ton SUV class that will do that. But given the loads the OP tows, I wouldn't say that is necessary.