I have done this, they think they are chickens and will not roam as a guinea gang. Lil stinkers!
I actually do this with the keets I plan to keep. They are far calmer and will not rob the brinks trucks for almost a year. The turkey ones turn out better than the chicken raised ones, BUT that could be because my turkey hen with Keets is a pet and the hen is just a hen from the flock.