What I learned about the different services on an IA (with 4 days notice that got pushed to give me a month - which actually just made it MORE painful) can be summed up in how I learned each approaches a problem:
A given task takes X number of people to properly accomplish:
Army: Assign 3X people to it so it will get done faster. In reality, the task only takes X people, so the other 2X have nothing to do, and just hate the system because they don't have enough to do and might as well be back at home.
Navy: Assign 1/3X people so that the work will be more challenging and cost effective. In reality, it gets done, but hurts like a sonofabitch, and those assigned just hate the system because they're worn down to the nub.
Air Force: Determine how long it will take X number of people to complete the task, then rotate 3X people through the job so they all get experience doing it. Job takes twice as long to complete, and everyone around them hates the system more because now they have to work harder to get the new Zoomie up to speed.
USMC: Break the task down, re-evaluate its manning requirements, and make it a collateral duty for the combined S-1/3/6.