Yes, the way I see it, the goal is to have a large quantity that can disperse as much as possible, while keeping each individual platform sufficiently large and capable to be relevant to the conflict you're fighting.
In fact I would say that approach can be seen in every military product that is being procured today.
I'm not sure if a twin engine (say, two non-AB WS-10s) would be appropriate as it would likely be at least as big as B-21 and it would be well and truly be much larger than a big tactical sized aircraft.
Unless you go for say, two non AB WS-13 sized engines, which is certainly an option.
Anyway, the goal of "greater quantity + greater ability to disperse" while retaining "useful capability for 2IC+ distances" I think is probably a useful way of thinking about what a "fixed wing penetrating strike bomber" may be, if indeed H-20 is being pushed back.