I'm not remotely interested in importing random fish, predatory or not. I suspect that many UK anglers would feel the same. We have quite enough predators in ruffe, perch, pike, zander, trout, and wels catfish. You can also chuck chub into the equation as one of the more aggressive omnivores. Even then, not all of those are indigenous to the UK. I'd not bat an eyelid if wels, zander and rainbow trout were eradicated.
I have to admit, I'm not, and never will be, a lure angler. However, I hope even ardent lure anglers would be against the unlikely prospect of any legal importation of random predatory species. I also hope that UK angling retains the significant differences from US angling that have existed for many decades. There's no issue in taking lessons, but wholesale mimicry, of the fishing from another continent, would be a terrible thing.
The OP seems to have the idea that there's something wrong with UK fishing because it's not the same as US fishing. I'd suggest that the different ways of fishing have developed because of the differences. Making either a clone of the other by interfering with what's natural would be a terrible idea.