There is more to leadership than just "economic performance."
Raila has his heart and mind in the right place. Social justice, equity, liberal leaning. It easy to see Raila is a liberal democrat - contrasted to say Ruto and his family/African values ala Moi conservativism.
Equally easy to conceive - Raila would cement ideology to breach the tribe. As a tool to change power dynamics. Most likely by classism/entitlements, feminism, gayism, minorityism - Leftist pillars. Ruto would ferment tribalism to consolidate power like Moi.
Now I don't know what "track record" has you place Ruto with Meles and Raila beneath Moi? Kibaki big infra binge - bypasses, highways - had Raila prints all over it. He was pulling Telkom dude arap Ng'eny house down to build Eastern bypass. Also the slum upgrade program. Very successful. It Raila brain Ruto SGR copycatted without introspection for an arm and a leg with dismal results.
Ruto best record is CDF, tightening college QA, ending admission slag. Nothing tangible. Under Jubilee 1 we have a mountain of debt as the outstanding legacy. But in record time Ruto has spread the gospel of corruption everywhere. Uhuru is making a name just cutting down Rutoism - free-for-all looting.