I think the Winnie, Thor ACE, Vegas/Axis, and the FR3 are probably your only options close to what you want. All of these are entry level. The shortest FR3 is 29' - still a few feet longer than you wanted and the ACE 27.2 is still almost 29'. And the Axis/Vegas is on the E450 Chassis. These are called crossover RV's. They bridge the gap between B+/small C's and A's. It's a niche, but manufacturers know that folks wanting higher end features also want more space and a better ride- thus a larger class A or a high end C. They know it wouldn't make sense to dump a bunch of money on a 26' class A on the F53 - no one would buy it. These crossovers are marketed as "weekender" and starter RV's. Heck the Axis is pretty much marketed as a soccer mom rv. No offense to anyone who owns one, I even know folks that full time in an Axis. I have looked them myself. But for the most part, their market share is the weekender/tailgater/starter.
Frankly I am not sure how Winnie shrunk their F53 chassis to get to 26' and still have a stable wheelbase - that thing might ride rough and loose. The wheelbase is only 158" - that's only 13'. I can't remember the calculation, but there is some math involved that the wheelbase should be more than a certain percentage of the overall length to provide a stable ride. The 26M is only 50% - if memory serves, the minimum benchmark for safe highway travel is about 55%. But something you could sort out in a good test drive.
The shortest "higher end" class A that I know of still in production is the Allegro Breeze DP. Used to be in a 28' - understandably still longer than you spec'd. If you want a higher end MH in your size range I think you'd be looking at a C on the MB sprinter chassis. The Tiffin wayfarer comes to mind.
The shorter class C's are not on the F53 and thus that's why the engine pairing is different.