One of the main grouses here is the lack of faster promotion opportunities that the older generation used to enjoy. This can result in dissatisfaction of younger teachers. Will it help to manage out older teachers who are doing minimum but already hitting their salary ceiling? Manage out meaning puting them on PIP for example.
This will not only motivate the younger workforce to know there's room for their progression but also, the GEO 5/5A won't be able to rest on their laurels.

Win win, you get a more motivated younger workforce and the older workforce get more talented.