Heel vs heel is doable if rare in WWE land. There is also the possibility of whoever it is that is being brought back tonight on RAW (a rumor) is there to feud with Roman.Would Roman go after Sheamus still then? I'd see it work if he attacked Ambrose tonight. But that'd be about it. He's not going to continue to go against The LoN, or feud with Triple H as a heel.
Or he has gone Sting. Chaotic Evil.