I long ago came to the conclusion that, when it comes to guitar playing, (as well as many other things in life), the difference between easy and difficult is really the difference between having learned to do it vs. not having learned yet. There have been numerous times when I thought a particular song was hard to play, took the time to work on it, and learned it. At that point I have often found my perception changing to believe it was really a lot easier all along. While I've never been in a band that tackled Help/Slipknot, I imagine the most difficult part is getting the arrangement right. It certainly isn't your typical 1-4-5 tune with the same changes repeating every 12 bars. I suspect getting everyone on the same page at the same time would take a little more work than most Dead tunes. But it ain't rocket science. It would certainly require everyone to do some homework though, and not everyone in an amateur or semi-pro band situation has the time or inclination to do a lot of homework between rehearsals. That's my $.02.
Bill, tgo