You've made our point for us in that paragraph. There is no improvement, there is no real progress and on that basis he doesn't deserve more time or more money.
Well if i would have said what you have suggested I did I can see why you would think that. The fact that I have not said what you have suggested sort of negates the rest of your post for me.
So where's the progress and improvement? Results? Points? League table? Performances?
2 years and really not much different to what he inherited.