Why would you assume that? He’s an international player and the PL is the most followed league in football. He’s already a big star in the PL. I know who the stars in La Liga are even though I don’t follow it closely.
And I didn’t mean branding outside of the UK specifically for that matter. They need to attract a shitload of new fans from all over the world including UK and Ireland before they can even begin to dream about having the same sized fanbase as United or Liverpool, which I’m guessing, is one of their long term goals.
Grealish is skilled, good looking, a media favourite, british and perfect for growing their fanbase the way I see it.
I’m sure he’ll be a success on the pitch as well, don’t get me wrong, but as others have pointed out, a striker should be a priority if you’re looking at the team isolated from the brand Man City.