Technically, no. You can only have one recovery image in the recovery partition at one time, and the bootloader will only find the recovery image that is there. That being said, I do seem to recall reading about somebody doing something to run a different recovery on top of another one. I don't remember where, though. I'll see what I can find. I have to ask, though, why exactly do you want to do that? It's not too hard to quickly switch between recovery images.