Hmm interesting, I don't know if I'd count "Take a Running Jump" as a builder-heavy level, at least it's different from the kinds of levels that typically comes to my mind. As far as I remember it's just about spam-assigning builders at the start as delay. The rest of the level actually uses comparatively few builders. It's almost like the builder equivalent to "With a Twist..." but less repetitive and much more forgiving in the spam-assignment part. It is a fair point though that putting it right next to "King of the Castle" might not have been the best placement.
I'm not sure I buy the comparison between Tricky 23 and 26, out of curiosity, which part of Tricky 23 is "fiddly execution"? Also for Tricky 26, while doing a builder wall is a legitimate strategy and at the same time a bit fiddly due to the high release rate, I think it's quite possible that they might have only intended on assigning builders to lemmings 2-N for delay only (without necessarily forming a perfect wall), similar to "Take a Running Jump". That being said, it's still fiddly for doing that, given the relatively lack of space and the high release rate.
This was the level that had me completely stumped and caused me to stop playing Lemmings for a while
It's a fair point, they really should've designed a progression system that allows you to skip levels after some number of tries, for example. And to be fair, they've definitely revamped the game progression systems in subsequent games in the series to be somewhat more forgiving in this regard.