The only ministry that I think MUST be under the president's loyalist is Security/Defense for obvious reasons. Would be surprised if there is a tug of war over Finance Secretary. If Ruto's side was to have it, it must be given to him as long as appointee is competent. Ultimately, all ministers will have to execute the President's orders given his power to dismiss and reassign secretaries. Principal secretaries will also provide check and balance.
The presidency even though clipped is still BY FAR the number one power vortex in the country.
All my friends are heathens, take it slow. Wait for them to ask you who you know. Please don't make any sudden moves.