I ment Z/Y not X/Y. It is true that I can rebind, but its annoying. Also I'm lefthanded, so those are more difficult to reach for me with my Thumb.
My Mouse doesn't have Thumb Buttons, and I'm assuming most don't. You shouldn't bind anything to Buttons that aren't default either.
I was strafing around the Skeleton, but that Combat is just too hard for me, with the directional Swings and avoiding the very long range attack of the Skeleton. Alongside with Healing not really being a Thing during that fight and the limited Space.