Care to tell me how and why the Mosquito is less of a bomber than the A20? The both have bomb bays, they both have foreward firing guns now. The only thing the A20 has that the mossi doesnt is a tail gun, a tail gun which is about as useful as tits on a bull.
The same reason why 110s are considered as a "fighter", or rather a "destroyer(zerst?er)", than a bomber. The same would apply to the Imperial Japanese Ki-45. The Bf110 and the Ki-45 was designed as "heavy fighter" from the start. The Mosquito was conceived as a bomber but was produced, served, and classifed as a fighter. AH's classification of aircraft as bomber/attacker/fighter is entirely US style, but other countries classified their fighters differently.
Could the same be said for the A-20? I think not.
The A-20 is an attacker, not a fighter. HTC didn't arbitrarily classify the Mossy as a fighter/attacker and an A-20 as an attacker/bomber. If the existence of an internal bombbay alone makes the Mossy a bomber, then the Yak-9B would also qualify as a bomber - which, clear is not. Therefore, quitely simply and logically, anything that is not a fighter is tied to the BH, not the FH, and all aircraft tied with the BH requires the existence of ordnance to be airborne. This is the arbitrary part.
So, if people really want A-20s enabled without ordnance, then they should ask all bombers or bomber/attacker class aircraft be able to take off without ord, rather than ask HT to grant a waiver to the A-20 only.