You are wrong on the US analogy :
1. Kenyan tiny counties are unviable unlike big rich US states. A US state governor is same as an African president
2. The US is not diverse but overwhelmingly monocultural English- speaking Caucassians. Few Latinos and Cherokees
3. The US did not start as a single country then break up into states. It was the reverse of states uniting
4. CoE went US template due to Naivasha PNU/ODM feuds not any objective analysis. Arguably the Bomas Draft was broadly debated and proposed parliamentary
5. The US has an electoral college ...
You differ with the US on too many points. Federal is good but counties need some years to develop GoK competencies. Doable.
I don't know how you arrive at the inability of MPs to oversight GoK. Jomo scrapped federal and parliamentary to escape accountability so he could loot and practise cronyism. As you can see devolution is working but for some reason you don't want to equally give parliamentary a chance. Increasing their salaries or mileage is addressable - tighten a few screws. PORK and his machinery remain wholly unaccoutable despite all commissions, vettings and whatnot. Kibicho runaway impunity should teach you something. The Executive needs to be grilled on his policies, choices and actions on an ongoing basis in a place full of impunity like Kenya. That's just plain sense - not brain haemorrhage
. Strip the Baba wa Taifa ceremonial nonsense, the conflict of assenting to laws that Uhuru abuse brazenly, etc. State vs GoK - I think that remains the key plank of presidential vs parliamentary. Couldn't come any sooner in Kenya.