Why 2 x E-3D Squadrons
It wasn't just the Sentry Training Squadron that wanted a number plate, there was at least one Wing Commander in the decision making process who was hoping to command a squadron.
Politics apart, I've always found it healthy to have some inter squadron comptetition, and it gives more options for those on the promotion ladder, even if they are ex F-3s and looking for a Squadron command. Having just the one squadron can make for an insular outlook.
It will be interesting to see which squadron their Airships decide to disband.