If the F-111 is given a more prominent strike role, might the USAF add some basic ground attack capabilites to the F-15 fighter variants or build a multirole variant, or would that see more roles for the F-16?
Also, how would the FB-111H have fared as a medium bomber for SAC, filling in the gap between the more tactical FB-111 and the more strategic B-52, B-1, and B-2?
Well with more F-111s in service you could either have the ground attack role in the above aircraft diminished; or the F-15 could have evolved into a true multi-role fighter early on, so in service it becomes a true Phantom replacement and would be ordered in larger numbers at the expense of the F-16 possibly. Maybe the RF-15 and F-15G Wild Weasel are bought as a result of this.
With the FB-111H around there would be no B-1, it was in competition with it after all. Because it's cheaper more will be ordered and you could see it lasting up to today and into the near future with avionics upgrades and the like. B-52 remains a missile carrier and it's entirely possible that more B-2 are bought without the massive expenses from the B-1 tying it down.