If they are wearing on the outside edges then it's an alignment issue. Too much toe in. My MH when I bought it sucked to drive. It was all over the road. The previous owner did a lot of suspension work including an alignment. I belive they traded it in because they couldn't get it to drive straight. Turns out the professional alignment that was done had the toe set at 5/8" toe out. The tires were new enough that they only showed very little inside feathering. I took a tape measure and checked and the toe was definitely out of spec. I found the specs on line and it should have been set at 3/16 or so toe in IIRC. So I did a tape measure alignment and it drives straight with no wander and no more tire wear.
So I would double check the alignment even if you had it checked some techs just don't care to do it properly.