Proper R/T procedures and phraseology are an absolute must. It’s easy to lose site of this if you are working in a local environment in your own language, but for the rest of the aviation world, English may not be their first language.
Not everyone works in inches mercury for altimeters, Mb's and Hpa’s are the norm outside North America. Transition levels are not the straight forward 18,000 feet as well as the use of feet or meters.
My rule of thumb; always convey R/T, checklist challenge and response as though the recipient does not speak English as their first language. In other words, clear, concise and standard.
I think you may find that under airmanship somewhere.
Cheers,