The REI Half Dome is a bog-standard dome tent, just about the definition of freestanding, but without at least two pegs, the vestibules covering the doors will flop around and provide no protection from the wind or rain. It isn't really pitched until those two corners are staked down. I've found that my Quarter Dome also needs the mid panel tie outs at the head and foot staked out for internal space.

You can put the inner tent up without any stakes, but it's a flimsy pitch, and you need a minimum of two stakes to pitch the fly.