Needs no practice whatsoever to whip out and play.
"I like this hero"
Heroes I would like to play. I enjoy their kits and would gladly grind the fuck out of them
Comfortable picks I can play at the same level of above-average/good. I understand them fairly well (though not completely) and can essentially manage.
Similar to above, but less consistent, less experienced, and more insecure.
Potentially It'd take very little to put them in the above tier. A simple game plan and build could be it, or they could need much more.
Could potentially pick these up through coaching and knowledge sharing. Vague understanding of them and what they do, needs to "click" and gain confidence.