CIA
Yeah definitely bigger than Gnr in the UK I wouldn't even say it's remotely close. Gnr were basically flavour of the month for a bit then essentially forgotten as trends changed. Don't het me wrong they have retained a pretty big core fan base but that's because they were great at what they did. But I wouldn't say they influenced popular culture in any way really.
Oasis on the other hand were in the center of popular culture from about 1994-1999. I don't know if influenced is the right word but they left a mark music, fashion etc in a way that dont think gnr ever did.
I suppose it's a British thing really and what you can get away with. It was easy for me to get a pair of Clark's shoes, a tidy Ben Sherman top and a feathered haircut and didnt really look too much of a bellend. Its a bit different if I got on the bus one morning in a pair of leather trousers, naked from the waist up wearing a fucking top hat.