Teaching match to sample via a transition from size discrimination.

About 7 years ago Coffee could do match to sample, but have not maintained that ability, and I was wondering if it would be easy to revive it, or even if it was being taught from scratch would it be made easier using an existing similar exercise after all the set ups and mechanics are very similar.
Also much of the cognitive work is similar, look at the article being displayed, (while on the mat) then look at the articles on the ground, make a decision and execute when you are ready. (definition of insanity?) This I fully understand, but I am explaining carefully that final decision effecting each of the 2 different outcomes.