Crab - I think those simplistic numbers you have used are a trifle naive. When presenting any business plan you also have to apportion a fair share of the basic overhead and you can bet your bottom dollar that the overhead for any military organisation is going to be very large (given its fundamentally different raison d'etre) when compared to any profit oriented commercial operator.
How many Captains/Group Captains, Commodores/Air Commodores, Air Marshalls and Admirals are there in UK forces?
How many aircraft/ships are there?
QED
G