I don't know about the Crowbar, but the lenses are not that easy to switch out on the Wisdoms. If you really want a 2 lens quiver, you'll probably want to consider making it a 2 goggle quiver.
I've had a pair of persimmon Wisdoms for a few years and the lenses had gotten pretty scratched up. I just picked up a new gold iridium lens for it, which should cover me on sunny days.
I was thinking of picking up a second lens for flat light and night skiing, but when I installed my new lens I realized this was something I would not want to be doing all the time.
I love the Wisdoms, and with the helmet strap they've worked great with my Giro G9. (the original standard strap did not work with my helmet) I decided to buy a second pair of Wisdoms, with the HI Yellow lens, figuring I could easily switch the 2 pair between my single helmet strap.
When I got the new pair, I found that Oakley had redesigned the strap since I had bought the old ones. The new Wisdom strap has soft, pliable pieces where the strap meets the frame. The strap is also longer than the original standard strap, and has strips of tacky material to grip the helmet. I found that the newly designed Wisdom straps fit great with and without the helmet.