Sequoia is beautiful; whether it's 'as beautiful' as Yosemite is debatable, but it is certainly not 'the pits' by any stretch of the imagination. My sister was a park ranger there for several years (now at North Cascades), and I've seen quite a bit of Sequoia/Kings Canyon National Parks. Most people don't get past the General Sherman Tree, so perhaps manneca is thinking just of that. My sister was always amazed that so many people would go to Sequoia & basically not get farther than Lodgepole.

Not being from NoCal & being unfamiliar w/ the various passes from Y/S to Vegas, I can't say whether dropping Yosemite for Sequoia would make more sense from a travel perspective.

I do agree w/ the others that your friends are trying to pack too much into too short a time & with driving distances won't have much time to actually enjoy what it is they want to see. I do agree w/ some of the above recommendations such as iapetus & menneca have mentioned.

BTW - if they do 'cram it all in', tell them they're not allowed to complain afterwards about the length of the drives & not really seeing all that they really wanted to see But tell them to have a great time regardless.

Cheers.