I'm thinking it will be OK. I will be flying Bostons/A-20's/Ju 88's/190F's in the scenario.
I've flown Ju 88's and Bostons a lot in scenarios. Bostons and Ju 88's are both in the mid tier of survivability. (Top being B-17/B-24/B-26/Tu-2; mid being Boston/Ju 88/Lanc; Mossie between top and mid.) Mainly because, although Bostons are fast, defensive guns on Boston are hard for most pilots to hit with. So Bostons take longer to catch, but once caught, have harder time than Ju 88 breaking off an attacker.
Also, as Rocco notes, 190F is a bit better jabo than A-20 (a little faster, better roll, smaller, harder to hit). So overall perhaps evens out.