And he is corrupt as hell yet he is not even at the top. GEMA will see that as a problem, not because corruption is a problem per se, but because he is not their man. He is not one of them. They only needed him to save one of their own from ICC fangs, something that is likely to have no relevance in 2022.
For GEMA, as I imagine they see it, it's a choice between
very bad (Ruto) and
probably really, really bad (some character from Nyanza/Ukambani/Western). I think they'll make the "logical" choice.
You say he will have no relevance in 2022. So what does GEMA do then? 2 (big ones) vs. 40
or 1 (big one) vs. 41 (including one new big recruit)?
The ICC ... it might be the case that "there is no honour among thieves", but thieves, if they do any thinking, will be mindful of their interests. The Central-RV marriage is like most marriages:
He/she did this to my relatives, was mean to them in this and that way .... I'm not getting any of the in+out. ... What a piece of work the dog/bitch is. But I'll stick with it for now ... the alimony, the kids, the threats of violence ...
And here's another thing: Going just by "anecdotal" evidence, I don't think much of the country is amused that GEMA is back, in full force to (re)-loot the country. I can't give any objective information on that, but I sense a lot of anger. That means they have to keep control. So while Ruto might not be their "our man", he is certainly their "our brother"---a bond lately cemented in travails in "neo-colonial" regions. A much-needed man.
The Opposition could capitalize on the above, but they are too clueless and disorganized: rigged internal elections, apathy in getting prospective voters to register, apathy in getting the vote out, a reputation for "hooliganism", etc.