Yeah, some people do need to heed the KISS principle a bit more. But there is no harm in discussing it for input.
For me and my type, distance times three works fine, then adjust for weather by simple logic... tailwind? Go down earlier. And remember that there is usually no ban on level flight during any descent or arrival
. So don’t stress it if you are off by a bit or too early on descent. Stay on the safe side. Also learn to say “unable” to ATC if you are unsure if you can do what is asked.