You are very correct about more units = more warranty issues, while percent stays the same. Thor Motor Coach (TMC) is no worse than any of the other mass production makers for issues at delivery.
Another part of the new RV experience is based on the dealer. A great dealer will properly prep the RV for pick-up and repair what goes wrong properly after delivery. Unfortunately, there are too many dealers that do not do a great job in these areas.
These point are true of any and all brands. So much so that owners of several premium motorhome brands make an annual pilgrimage to the factory service center...they even have pet names for this Mecca. You can see these pet names in those owner's forums. TMC also has a factory service center that has rave reviews if that become a need.
The 3 TMC lines mentioned are the "entry level" gas coaches (ACE, WindSport, and Hurricane). These are beautiful and affordable RV's.
And being entry level just means that there are less options than the Miramar and Challenger...plus, the ACE has been North America's best selling gas Class A for the last 4 years.
These RV's are made with commonly available components and are easy and affordable to repair - unlike brands that use proprietary parts and systems
Having said all that...The buyer of ANY motorhome should have "eyes wide open" and double check everything in the coach before closing the purchase. The dealer should provide a Pre-Delivery Inspection where the buyer can check everything. We did not accept our RV until every item on our check was corrected. If there are parts to order, the buyer must decide the correct path, but if repairs are done after pick-up, the buyer has lost the pressure provided from the sales staff.
Pick the RV that YOU like...that's what matters.
TMC offers motorhomes with most everything as standard equipment (few optional items). They pre-sell every RV built, to a dealer (no special/custom orders & no debt). And there is no factory pick-up. All these things help keep price points as low as you will see in the industry.
Finally, about the cliche' term "Thor Quality": Thor RV is many-many brands from Airstream to Coleman, Entegra to TMC, and Dutchman to DRV Luxury Suites. That should say something not often said about quality.
https://www.thorindustries.com/get-t...the-companies/
Best luck