Overall I think you dodged the point I was making, but nevertheless after some thought I have decided to give Endeavor the third slash in the main moveset, eliminating Whirlwind from the analysis. I see the merit in using it, but I still see more merit in using the other two in the majority of matches (and you have in no way convinced me otherwise with the arguments you made in this thread). And Endeavor does still have its large faults in that, "Ok I bring you down to 1HP, but now you can setup even more with nothing to fear." To convince me to make it the primary/only slash, I'd much rather you post logs of matches or at least scenarios where Endeavor is overall better than the other 2 options, rather than just posting that a named player supports one option as that gets us essentially nowhere as numerous "named" players also support the opposing side.
Anyways, Whirlwinds main use was to employ use of hazards while preventing setup sweepers, the latter of which is done better by memento and the former can also be done by Endeavor.