sorry guys it was late when posted

I have a temporary building needing 600a to feed 3-200 panels installed on Temp Buildings. the service to supply the Temp Building is 150' away and needs to be run overhead. The existing service is 800a and not being used because of construction. It has 4-200a disconnects on service not being used. at first I wanted to used the 200a disconnects to supply the 3- Temp building but discovered they are grouping all three together to make 1 building. i now violate 225.30. im just looking for better ideas thsn mine.