Ok, I now have evidence that you can save 100% on Wicked 13 with no more than 9 builders.
I said "evidence" because my attempt was screwed up in a number of places. First, I used 2 more builders than intended, because I failed to build at the intended places (basically, the same frustration LemSteven went thru when confirm the 10-builder solution, except I didn't feel like starting over). Second, at the beginning I accidentally lost one. And I probably used more skills towards the end than really necessary (but fortunately there was enough).
Still, the solution idea definitely will work. It is actually just the 10-builder solution with a different way to deal with the "ending". No differences until after you got past the application of the Mayhem 12 glitch.
--------------------
As for the Mac, with great difficulty (it's very hard to do precision moves on it reliably), I managed to confirm the 10-builder solution.
Although earlier I said that the 9-builder solution is probably PC-specific, I'm beginning to think that might not necessarily be the case. In particular, since the glitch for the builderless Tricky 9 seems to work to some extent on the Mac......
Still, I don't think I'm even going bother with the Mac until I actually confirm the 9-builder solution for real on the PC first.