The space isn't the issue, the square footage is acceptable. Unless he is rotating he WILL have worm problems. That is a set-up for a parisite storm. Big concern is turkeys in with the chickens. There are a lot of diseses that chickens carry without a problem that will kill a turkey.
I allow 6 sq feet per goat for housing (under cover), open acces to pasture and a light stocking rate of about 3 goats per acre. Without pasture they need 1 square bale of hay per 8 goats per day, plus grain or corn and a free fed mineral suppliment. I know people that go as low as 3.5 square feet under cover and 8 goats grazing per acre without problems but they ROTATE!