If you can't defend it (Gili Gili comes to mind as the most famous of these), don't take it in the first place. If you do not have AA units to pop on the spot to make training runs somewhat costly and some form of LR/CAP to feed on the training pilots, leave it be.
I have no problem with training like this as it is pretty much as close to real world as you get. As someone who went the private pilot path, I can tell you that every little circuit around the airport builds skills. Going off to bomb stationary rocks that happen to be nearby is perfectly valid.
The concern I have is that skill gains vs survival will NOT balance out which means pilots will DIE before getting enough skill to NOT DIE
Having had both F4F-4 & F4F-3 airgroups on Lexington & Yorktown both upgrade and shuffle in a pile of average 30 skill pilots while I was out at sea COST me almost 30 aircraft that very turn. I'm glad they have disabled this upgrade while at sea now, cause this happening in the middle of a patrol forces you to fly these suicidal newbies. It adds another level of micro management that the game can do without, having to baby sit each squadron just in case new pilots show up so you do not get mass graves that following turn.







