Here's an idea inspired by PantherG's profiles: a Boulton-Paul Defiant gunship.
Let's say a Defiant user realises that the turret-fighter concept is dead, but they can't afford to just relegate the airframes to target-towing. One thing they might do is take the turret off to save weight, and then re-fit the guns (and maybe more guns) in the same place but fixed to fire sideways (I think downwards is out because of the radiator) for straffing ground targets.
The RAF had an interest in 'beach-straffing' in the days when invasion looked credible, which led to that bizzare Delanne biplane Lysander with a rear turret. The Defiant conversion would be much simpler and probably just as effective. Alternatively, you could sell the Defiant to somebody else (Finland was my favorite, but PantherG has also done a Netherlands profile) and they could do it. The Netherlands home forces wouldn't get much chance to learn lessons and convert planes before they were overrun, but maybe the units in the Far East would, particularly when you consider how the standard Defiant might have fared against the Zero...
