I like McWilliams but who would he replace? Grimes, Crooks or JJOT.
See my team posted earlier, I would only play one of Crooks/Grimes in the central "advanced" role with McWilliams next to JJ in a 4-2-3-1.
My temptation would be to send Grimes back and tell Crooks to man up and show the form that made us sign him, but don't think we have room for both in our side. Crooks does add some height to the forward area and he is our player so should be bothered about where we end up.