I've had mounting issues with some Gatorskins and Panaracer Paselas. I used Michelin Krylion for a couple of years and dont remember having much trouble mounting or dismounting them. I just didn't like the way they ride. Have you tried the Tire Jack by Koolstop? I got one for Christmas, and it works great for stubborn clincher mounting. I still use plastic levers for dismounting. I like the thicker ones like Pedro's or the shiny slick plastic Park ones are good too. I've broken several other plastic ones. Never used metal "irons".
Pretty simple, works great. Its a little big to carry in a jersey pocket but I'm tempted.
Here's the Tire Bead Jack on Amazon:
https://www.amazon.com/Kool-Stop-Tir...54439296&psc=1