They could ship ... but to whom? Marketing and market timing and product-market fit. (Ref: why didn't Smalltalk take over the world)

That still kind of making my point. The right product at the wrong time is the wrong product. Post 1997 Apple, there was Jobs, Cook, Schiller, Ive and Forstall among others that actually focused on shipping products instead of letting the “smart people” run wild.

All indications is that they balanced each other out as leaders.

True. But I don't think it is just that.