I haven't pulled anything with other models, but I was not happy with the towing characteristics of my '22 Timberline when I pulled a small excavator for a friend of mine. The rear end squats pretty low under load. There was a lot of body sway with any movement of the wheel, and going around curves. I have since added SUMO spring helpers on all 4 corners to help reduce the suspension compression under load, and replaced the rear anti-sway bar with a stiffer one from Hellwig. Since you will be pulling the same trailer most of the time, you can probably get one of the True Tow heavy-duty weight distribution systems from Weigh Safe that would help with all of that, also.
The high output EB, lower gears, and the additional cooling fans on the intercooler are advantages for the Timberline that most of the other models don't have. The intercooler can become heat-soaked during towing in certain situations, causing the ECU to retard the timing and reduce power if there isn't any active cooling. I took an additional step and replaced the factory intercooler with an in-place upgrade with 80% more capacity.
The tremor is supposed to have the extra fans on the intercooler which should help a little but I don't know if that alone is enough.
I had a 2019 with bilstein shocks and felt like that performed better towing than my 2020 with the CCD. I have added the hellwig anti-sway bar and that did help. I still think the Tremor will need the better swaybar and at the end of the day the rear springs are probably still not up to the task of a heavy trailer. The sumo springs are probably needed but I wouldn't think they would be needed on the front.
A good weight distributing hitch that is SETUP CORRECTLY will be needed for sure.
I still don't think the cooling cuts it on the expedition. The transmission cooling is not good. I wish I had time now but I am going to upgrade my transmission cooling and likely add an intercooler, and get rid of the stupid dampers in front of the intercooler/radiator and possibly adding an engine oil cooler as well. I'm still considering a lower temp thermostat but I am not sure if that will do much but it's cheap and might be worth doing anyway.
Towing this weekend in 100 deg weather I had issues keeping the engine temps down, which then leads to the transmission temps climbing, which leads to reduced power which leads to more heat...I was hitting 240-242 at times chugging along in the slow lane. I tow this same route multiple times a year and never climb above 228 but with the high outside temps this time it was noticeable and I was going slower than normal.
When temps are sub-90 I seem to be fine almost all the time but there just isn't enough cooling when the temps are high. My hope is keeping the transmission separate will help, not sure how much difference the intercooler will do when it comes to engine temps.
Just for reference, my trailer is 23' and loaded probably around 7500#. Our most frequent trips take us over multiple passes at 6800ft. We have a few trips that take us over passes in the 8-9k range. I had one trip down to the mountains outside vegas where I actually had to pull over and let the rig cool down before proceeding. Other people were also pulled over doing the same thing. It was a long hot grade.
