The 2922 has a king bed in the rear and the 2720 has a queen bed. 78" wide vs 60" wide". That accounts for 18" of the 24" difference between 2720 and 2922. Which puts at least 18"of the 24" behind the fulcrum point of the axle. Being behind the fulcrum would make the tongue lighter? Not sure where the other 6" are. The storage in the 2922 is at least 2x as deep as a 2720, which could even make things worse if you pack the rear storage heavy. I know my DW would use all that space.
The 2922 at 8%?? If it's correct, I wonder if that had anything to do with posts I have seen from time-to-time about sway issues. It's the only TM models I have ever read post about sway issues. If I had a issue, I think I would consider hauling with a full fresh tank which is ahead of the axle.
Our 3023 compared to our old 2720. Same queen bed and rear storage depth. On the bottom shell I can not see a difference from axle back compared to a 2720. The increase of 3' seems as if it's all ahead of the axle, which I believe should give us a greater tongue percentage than a 2720.