By choosing existing airframe, engines and guns, what kind of a twin/three-engined bomber would you like to see in service, in 300 copies at least for 2nd half of 1941? As German, you need to defeat Communists quickly, as a Soviet you need to beat back Nazis beyond Berlin, as an Japanese you are fighting in vast Asian territory...
The god blend of firepower (bombs, guns...), range vs. payload, cruising max speed, survivability when contested by fighters AAA, reasonable performance from deck to 20K is what is required.
You may choose to design two types if you like, one lighter, another heavier type. Eg. if you feel like having German engine mounted on Italian airframe, featuring British guns, go ahead and post something about it
The god blend of firepower (bombs, guns...), range vs. payload, cruising max speed, survivability when contested by fighters AAA, reasonable performance from deck to 20K is what is required.
You may choose to design two types if you like, one lighter, another heavier type. Eg. if you feel like having German engine mounted on Italian airframe, featuring British guns, go ahead and post something about it