All victory conditions should become boolean options, so that we can play with an arbitrary set of victory conditions. For the same reason the "last man standing" mode wasn't made some victory condition but consciously setup as a boolean.
The "survival of the fittest " "mode" would just be another checkbox. It also wouldn't become a victory condition because it doesn't have to decide when someone has won.
Same goes for the "nomad" "mode" btw, every map should support that, independent of all other "modes", I hope we can do all of that next for alpha 22 :-)