Chris, what elbow sleeves are you talking about??? I have SBD’s, and they add exactly 0 pounds to my bench. Are you sure you’re not talking about the slingshot?
I do agree that you should be able to put the sleeves on yourself. They’re mostly just for warmth and comfort, not so much a ton of compression.
The cuffs, on the other hand, should be tighter. I would get a size or 2 smaller than your actual measurement on those. Potententially even 3 sizes. I have a friend with 20" forearms and he uses 14" cuffs. They’re hard as fuck for him to put on, but he can make it work. My cuffs are 2-3 sizes smaller than what I measure.
Basically, I use my sleeves for overhead pressing, and for strongman training in general. They keep me warm throughout training, and they help with the ‘regular’ aches and pains and stuff. The compression cuffs are more for tendonitis. When I’ve developed tendonitis from tight forearms and triceps, the cuffs have helped tremendously.