You guys have it all wrong. In America, when trying to build a fan base, we don't stick with just naming teams after cities. We expand the pie and use states or regions. Like the Minnesota Vikings, the Carolina Panthers, the Golden State (i.e. California) Warriors, etc.
I am sure the NFL wants all of England to support the new side. So it will be the England something. And because this is the NFL, where the brain trust and fan base has rarely emerged from the trailer parks in which they live to see the world, the name will probably reflect a uniquely American perspective of your lovely land.
Such as . . . the England Fish and Chips, the England Orthodontist Visits or the England James Bonds.