To clarify, I was discussing the merits of buying a stack of 4 bombers and sending them to the Pacific.
Sure one bomber might get some targets to snipe at - but a full round buy doesn’t add much to what you already got with the starting bomber. Anything can be effective against an opponent making serious mistakes like leaving a transport stack naked and open to attack, and in a case like that, one bomber is as effective as four.
The issue is with the mechanics of movement over the oceans. A Japanese transport at a harbor can be in range to attack a bomber while the bomber is not in range to attack the transport, despite the vast difference in base movement - an airfield for the bomber makes no difference. Land units can effectively move 5 spaces to attack when using a transport at a harbor (one load, three move, one drop). The bomber would need 8 move total to attack that transport and return to base, and of course it only gets 7 with the airport and 6 without.
It’s totally counterintuitive when you look at base move 2 for ships and base move 6 for bombers, but in practice, that transport can attack from one space further away than the bomber can.
In order for this to work you obviously cannot takeoff and land at the same territory. The Pacific allows for many landing areas so this is not necessarily a problem. Some good bomber moves in the north are to bring bombers from Hawaii to attack SZ 6 and land in Midway, and to take bombers in Midway and attack Japan and land in Amur. That extra move is what really makes the difference.