In my textbook of organic chemistry by francis carey 11th edition, the Corey-house synthesis is elaborated on in the topic of organocopper reagents. It is mentioned that as the R-X alkyl halide is added to the [R-Cu-R]- group, the electron count of copper increases from 14 to 16 and the oxidation state increases from +1 to +3. I interpreted this as a "driving force" to make sense of why this reaction occurs and why it was mentioned. the driving force being that as long as the reaction makes the electron count of copper approach 18, it is favoured.
however this driving force does not hold for the reductive elimination part of the Corey-House synthesis where the electron count of copper is reduced from 16 to 14. it was mentioned that this decreases the oxidation state from +3 to +1.
It seems very strange to me that in the oxidative addition, the reaction is favoured due to increase of electron count but the reductive elimination is favoured due to a more preferrable oxidation state of copper. it does not feel fair as it can be seen the other way around, where oxidative addition is not favoured due to change in oxidation state and reductive elimination is not favoured due to change in electron count.
So my questions would be what exactly drives the reaction forward? It does not feel right to use separate driving forces for this scenario. And instead of oxidative addition and reductive elimination, is it possible that the ligands reversibly bind to the copper? and the R-R' desired product is formed when the reverse reaction occurs,where they are unbound from the copper and bind to each other