Units are built the way the dealer orders them. A dealer in Minnesota may opt to always order the Arctic Pac tank heaters but may order 13.5k BTU A/Cs, because that’s what their customers might want. Florida and Texas dealers may skip the Arctic Pac but definitely order the bigger 15K A/C. If a dealer has a hard time selling Trekker cap class C units, they may chose to order them all with over cab bunks. Some dealers may order every available option.
If you order your RV and wait for it to be built, you can chose whatever you want from the available options. Other than the options chosen, I believe they’re all the same for the country they are built for.
At one time we were interested in the Thor Axis or Vegas RV. The dealer said there were no options or deletes permitted. Other than the exterior color, the units were all built the same way. We decided against that product for a number of reasons, but the lack of customization options was a factor.
2020 Sunseeker 2440DS Ford, Trekker cap, Topaz paint