Kayteg1, completely hypothetical since I have a F450, and if we are talking towing, a slight difference in wheelbase with a light truck gets owned by the heavy one even with an improvement of the light one's COG. And ...of course, the COG calculation changes dramatically of the entire rig/trailer. Sounds like apples and watermelons to me.
BTW, there are several people who have noted almost no significant change to front weights when adding a TC. A few inches might be better, but a crew cab longer wheelbase has an advantage over shorter as well. Then, a diesel has more weight on the front as well, so all TC carrying trucks should be diesel right? Just to improve COG ... ;)