Well if a person isn't complying, cops do have the right to bring them in by force... Of course that doesn't mean they should beat someone up like that Houston cop in the other thread. I don't know if there are any rules on how long a cop should try to get someone to comply by verbal coaxing until using physical force.
And again, you could be the world's most charismatic and charming cop, there's still going to be people who talk back and won't comply, no matter what words you string together. While UK cops receive more and better training than US cops, I don't think they're that much better at non-violent conflict resolution than US cops. The prevalence of guns is imo, what makes for the difference between UK and US police shootings. A society that's in a constant Mexican standoff is a dysfunctional society.