I always equated "Cherry" with being new.... 
what you describe I would think just falls into the "Bnz-picker" category
that's your interest in classic cars comng thru...
your defintiion of BNZ picker would be one of the sub-definition so of a cherry pick, altho' by nature most cherry picks, and picks in general, are performed at high speeds.
For example, let's say you were running... errr, dragging someone(s) on your six, and I wandered by from above and dove down to clear you. That would be a pick (actually it'd be a drag-n-bag, which is a subset of "picks") if they didn't see me, but it wouldn't be a cherry pick, even if the guy(s) who died were total noobs.
Ugh getting complicated, lol.
but basically Pick = nailing someone who was either unaware, or unable to counter.