Me being a smartazz..
Actually during Vietnam we did have some Army Intel guys serving on Navy ships assisting with navigation and targeting on the bombing raids. Part of it was really just military BS bureaucracy. The Navy's illuminated grid squares wouldn't fit or work on the Army's ground topographic maps and visa versa and neither service would allow the other access to their supply or suppliers, so Army Intel guys had to install their grid squares on the maps so Navy guys could navigate and bomb at night. There were other inter-service equipment issues as well like radio squelch, Navy pilots couldn't talk to Army spotters because of different squelch manufactures. Just a frigging mess all around.