4th Fleet (nearly useless - command radius 1)
SE Area Fleet - useful (command radius 4 or 5)
Combined Fleet - very useful (command radius 9)
Any Japanese stupid enough to use these for Betty bases instead of the naval repair assistance that they are, deserves what he will receive. 4th fleet goes to Truk. SE Fleet to Rabaul and Combined stays in the home islands.
Southern Army - very useful (command radius 9)
Right, so you can base a bunch of Bettys in Malaya or Sumatra....the Philippines? (Why anyone would move it there is beyond me). I tend to put this one in Bangkok or Singapore so I can reinforce air groups.
2nd, 3rd and 5th Air Divisions (useless as a personal house rule prevents me from assigning naval torpedo squadrons to Army commands - I'm assuming torpedo ordnance can only be drawn from the air unit's chain of command)
Useful.
21st-24th Air Flotillas (nearly useless - command radius 1)
You are going to want these on your primary bases so you can get coordinated strikes. Same for the Army air divisions. You aren't going to set these up worrying about how Betties will get torps from them.
11th Air Fleet - useful (command radius 4 or 5)
11th Air Fleet for Rabaul. Of course, no one expects Betties at Rabaul, right? [8|]
If you add to this michaelM's note about supply requirements, it's going to be pretty darned hard for me to get Betty's and Nells into newly captured airfields and have them operating with torpedoes.
And it will be even harder keeping it supplied unless you put the effort into building the port. Which will take time. Far easier to put the Betties in their logical locations where they will be up to speed much more quickly.
Putting Betties at tiny bases might be an emergency choice, but it isn't a sustainable option.
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