Much depends upon if your using a combiner box on the roof for multiple panels, and then running a heavy gauge down to the solar controller. Or, running the individual wires down to be closer to the solar controller.
Higher voltage solar panels, are pretty good at doing the individual separate runs down. Lower voltage panels work well with a roof top combiner box, and then thicker gauge run down.
We went with the higher voltage panels, and then had the ability to add a circuit breakers for each of the individual runs down to the controller. This allows you to isolate a problem panel, and to also check the output of each individual panel by the simple switch off of a circuit breaker.
Not familiar with your coaches layout.We put a combiner box on the roof top (Not to combine, but because it was easier to water proof seal this box tot he top of the roof. I also used this access to feed WiFi and Cellular cables down into the coach as well.) directly above our bedroom TV cabinet. We removed the tube TV, added the circuit breaker box to the back of the cabinet, ran the cables thru the combiner box on the roof down into the cabinet and to the circuit breaker, and from there, down into the compartment that housed our fuel filters (on the 04 Allure, this is the rear passenger side basement cabinet, which is right next to the battery compartment cabinet. The MidNite Classic 150, had connections for all five of our panels (240W 48V), and we mounted this to the ceiling of the full filter cabinet. Then we fed the fat cables thru to the battery compartment. We added a shunt valve to feed our meter (Magnum BMK-ME), and form the shunt valve to the battery and chassis as appropriate. IMO, the shortest run possible on your final 'fat cable' feed to the battery area, is the best way to reduce power loss.
To finish off on the TV Cabinet, we decided to not replace the TV, but adde a removable shelf, and some matching cheery doors, and have more storage now. While still retaining access to the circuit breaker as needed.
Our alternative location, was to place the rooftop combiner box above the closet, and run the cables down thru to the at same fuel filter cabinet.
No right or wrong not this process. And pro's and con's need to be considered.
One suggest I recall getting that I felt was spot on, was to 'upsize' the cabling and major components, to add for additional solar panels if ever desired. (The labor of installing, running and hooking up all of this stuff, can be expensive. Even if doing it yourself, paying a it more for a father cable, or a bit bigger controller, or even a bigger rooftop combiner box - is worth the added costs to allow for the flexibility of adding more panels at a later time. (I was going to only install 3 240W 48V panels. But planned for more capacity in the full system. I'm glad I did, as when I called to place the final order, the gent was able to shave about $45 off for each additional panel above 3, so $220 savings for 5 panels - thus, I ended up going for 5. ($20 off if I added only 1 panel.). I never quite understood the reason why, but was glad to get the costs down and also shipping freight costs were the same fore 5 as they would have been for 3. If I had bought one more panel, or two, later on - I would have had the same shipping freight costs repeated. So, I bit the bullet, and put the DW on Bag-O-Wine for a few months, to absorb the hit of the two extra panels
Best of luck to you on your project!!!