Something I think Mark was looking for in his solo band was multi-instrumentalists and Glenn had his "large instrument" on stage for some tunes. How else could they play Bonaparte, for example? Unfortunately it sounded like he was playing his own tunes at times. Just listen to him playing over the twiddly bits during Sultans - what on earth is he playing?!!! John was happy to take a back seat and do his job. To me that is professionalism.
For me the bass is a background instrument and something you shouldn't really hear until it's gone. John played to that rule, Glenn wanted to be heard.
I have no problem with Glenn approach of SOS.
It is to the least approved by Mark, and to the most asked by Mark
So I would say
Mark wanted Glenn to be heard.
Mark is the absolute boss and not one single note is played without his go.
Then there is the way the fans receive it but that is another story.
Glenn is doing too much? Maybe but that is a sum of individual tastes.
I remember Manu Katché about why he changed his drumming approach on Heavy Fuel, and how Manu saw Mark in the control room going instantly nuts about that playing.
Action, reaction.