That Bohl's teams at Wyoming struggled to be upper half in offensive production is not really debatable. What is debatable is why. One reason talent level and one reason is strategy or scheme. Let's talk about the talent side of this. You already have pointed out that the 2016 version of Bohl-ball was not totally offensively challenged due to the higher talent level at the skill positions. You seem to think that Bohl did not prioritize recruiting talented players, particularly at QB, after 2016. That feels like a big leap. I won't argue that he never got any noteworthy talent to speak of after having Allen, but I can't get on board that there was some intention behind that.
I think the years before and after Allen under many coaches shows us that great QB's (and players in general) are really hard to find.....and to the extent that you are sure they are great, it's extremely unlikely they will choose to come to UW. To me, that leaves us right back at what Bohl was actually pretty good at...creating talent. That was mostly seen on the defensive side of the ball and on the offensive line. That particular talent is probably harder (somewhat) to identify in high schoolers than a great WR or QB. That means that the obvious WR and QB talent is being sucked up by bigger fish than UW while Bohl and other Wyoming coaches are left trying to build up those players through development (which is what happened for Allen btw). Doesn't mean that you can't do it...but it does heavily imply that having great WR and QB talent at a school like Wyoming is nowhere close to a given no matter how much you focus on it.
Now ... as far as strategy/scheme is concerned... Bohl definitely was going for a style of smashmouth ball control that meant that the passing game was not focused on much. A bit outdated...but not entirely unsuccessful.
