Our guinea was raised with chickens. got both as day old hatches. Raised in the house together. Then moved to the porch together. When they FINALLY made it to the barn they went together.
Into the coop together. Around that time is was late fall/early winter. The bigger chickens didn't venture outside to often after the snow fell. So the younger chickens and guineas stuck with the bigger ones.
They pretty much stayed very very close to the barn. By the time spring came around and they were ready to venture again they are still together.
The guinea roosts, eats, walks, explores, dust baths, EVERYTHING with the chickens. Once in a blue moon will they be walking ontop the run or barn...But very seldom are the guinea NOT with the chickens. It's been about a year now, and so far so good. We also have a farm up the road that has guineas. They will come down here and visit every once in awhile. Before we had chickens (2 years ago) the other farms guineas would roost in the trees in our front yard over night.