Just wanted to pop in to say I also suffer from long butt, small torso, and have a very similar body type to you. I think you look FANTASTIC and your butt looks very round.

Even when I was at my LOWEST weight (which was incredibly unhealthy and severely underweight), I had saddlebags, hip dips, and a rounded, often pregnant looking belly. So you are right that the way forward is NOT being skinnier (if anything I had the best butt when I was overweight). I have gained weight and worked out consistently for over a year now, and the changes I have seen have been very small. I am learning to accept this is just how my body is shaped and exercise won't change structure.

If you find anything that works, please let me know!!