I think the Red is a Haddoni while the green is a Gigantea.
You can certainly house them both in a 60 g cube if you are able to get them not to move. Haddoni and Gigantea can touch without seemingly cause problem. Mine does for at least 3 months now and both doing well.
IME, these anemones does not move around much at all, unless you got your pH low. If I overdose on my Ca reactor, my Haddoni will start to walk, especially at night when the pH get low to about 7.8 or so.