Here is the Okinawa's strategy. I have made the spawn points arrows like US invasion ways in the real life in 1945:
As you can see, the best coast to start invasion is Yontan and Kadena area, like in history. After capturing those fields Allied can roll to south and north using GV's spawn point's ways.
There are numbers of automatic 20-30 mm and mannable 37 mm Acks all over the island and always near the spawn points. Those Ack batteries are owned by the nearest field. Maybe the best way to invasion is destroy at first the Shore and Ack Batteries with heavy jabo attacks.
Ack Batteries have always three guns: automatic 20 mm and 30 mm and mannable 37 mm. The heavy 88 mm batteries have three gun's too. Both battery types are placed like triangles.
Capturing the fields is the old system: maprooms are always near towers and there are any "Field Cap Towns" in this map. That's because of frame rates, there are a lot of trees and stuff in the fields... you know me!:D Kill the VH and Acks and drop the troops.
There are no Hangers on the fields, but all the Sandbag Revitments are like them.
Five Airfields on Okinawa Isle has their historical layout with coral runaways and revitment's places. The little isles around Okinawa have little "jungle" fields. They are like quickly built bases or little reserve fields. They have Shore Batteries, too.
HQ's and Ports are outside the Clipboard map, so you cannot see them.
And the Allied fleets are Huge looking from the air...