I can see Adkins winning this race, albeit closely. He has a strong following in Eastern KY and would negate some of the margins Quarles could pick up in rural areas. Andy Beshear would also help him in Western KY too. Add in the support he could generate in Louisville/Lexington by virtue of being a Democrat (although I'm sure his pro-gun and pro-life policies would anger far-left groups) and it's not hard to imagine him winning.
Imagining a Governor Mike Harmon is an interesting scenario, though, because I actually moderated a debate he was in when he ran for state representative in my area in 2002. I could see it happen too because some GOP challengers might think Beshear is too tough to beat in 2023 and opt out, opening the door for a socially conservative challenger like Harmon.
I still think this scenario would lead to Attorney General Daniel Cameron getting the R nod, though, as he's a Mitch protege and Mitch is already trying to position him as a national figure, hence the RNC speech.
But Cameron would be damaged by the Breonna Taylor case.
Can he win Lexington/Louisville/Frankfort?
There's no way a Republican is going to win Lexington/Louisville. All you can do is keep the margins down or hope for bad Dem turnout there, which is why Bevin did well against Conway in 2015. Conway didn't get a lot of support in Louisville and Bevin peeled off some votes with charter schools support because the JCPS school system is a wreck. Of course, for Dems to win a statewide race they have to have SOME rural support because KY isn't that urbanized (only one major city in the whole state) so an urban-centric coalition can't be duplicated here and that's been a challenge for the party since the Obama years.
For a Senate race, Mitch is sending signals that Cameron is his choice for an heir apparent. Personally, I'm not impressed but that's just how I see it. Quarles is more likely to seek the governorship in 2023 and based on how well Beshear is remembered for COVID, it could be a tough race because Quarles is really popular in the rural areas and could erode a lot of Beshear numbers in Western KY.