Roundhouse needs to provide door center line spacing and degree of separation which obviously matches the track center line. You need to either lay the track to match the round house or custom build the RH to match the track. Fudging can be done but it can get a bit whimsical when you see curved tracks entering the door ways on each end of the RH.
In my case I will need a custom built asymmetrical RH.
RH and TT can gobble a lot of real estate.