The exact positioning is comical. Even just saying "we punch way above our weight" would have worked and been less easily ridiculed. Then you can avoid the silly military imagery.

The UK does have a lot of soft power-- France and Germany haven't delivered much pop culture with the global impact of The Beatles or Doctor Who. Even if they're owned by foreigners, Rolls-Royce is still a global shorthand for luxury. The world does gawk at their royal family in a way that they don't at, say, Emperor Naurhito. There are probably ways to lean into that, but they require being a place to incubate cool stuff, not turning into a financial playground that happens to have a rest-of-the-nation attached.