You are assuming that the spec dry weights are correct. Usually that does not include "options" you might have that weigh something, that you thought were included in that dry weight.
Options might include fibreglass sides instead of aluminum (add 500 lbs) double pane instead of single pane windows, winter grade insulation package, air conditioner, whatever.
Note your spec dry pin weight percentage is 20% (2700/13400) but your measured 3220/17500 is 18%. At GVWR 16500 and 20%, pin would be 3300. No effect on overall weights, but you might be loaded to the rear of the axles, or else nose high when hitched. You can adjust the hitch and king pin heights to get level if need be.
This says the 13,400 UVW "is based on average weight" whatever that really means
https://www.granddesignrv.com/showroom/2019/toy-hauler/momentum/floorplans/354mAt 16500 GVWR with pin at 3300, that leaves axle wt at 13,200 which gives you 800 margin under the 2-7000. So compared with UVW axle of 13400-2700 = 10,700 that gives you 13200-10700 = 2500 you can add to axle wt. IMO your 39 ft rig should have three axles. I have seen toy haulers that long with three. Oh well.
https://www.rvusa.com/rv-guide/2008-fleetwood-gearbox-toy-hauler-floorplan-395fs3g-tr3484
