SEGunner actually many hangars are that close. They were like that in WWII also. The major difference in airfields from WWII as compared to ours is the reventments and hardstands. This is something we don't have. They had HASs, reventments, hardstands and maintenance hangars.
Even the flow through hangars we use in todays Air Force are close together. Our forward deployed bases are a bit different though. Depending on the airfield we can have all of our jets in a row under flow throughs or in HASs which are spread out much like the reventments or hardstands were in WWII. Again though it depends on the airfields build. You could have all your birds lined up in a row on an open ramp or in a line of reventments.
I'd prefer to see reventments or hardstands in AH2. None of this magically appear on the runway stuff. You'd pick a reventment to launch from and be off on your way. This is realistic though and alot of folks don't want realistic. This would also help out on the whole friendly collision thing. Again though friendly collision will never be implemented so no need for this type of setup. You'd basically have to wait in line for the reventments to launch if they were being used at that time. Or it could have a setup option to select any unused reventment automatically and just spawn you at any reventment.
I've got a book that shows WWII style base setups for the 8th Air Force in England. It's got about 50 bases or so and shows how the whole airfield was setup. It includes all the buildings, taxi ways, runways, reventments, and maintenance hangars. The book even tells you what the runways were made of, how long they were and who built them. Might have to post some pics of it someday.