Why do you talk about athletics? Baristas are not athletes. Coffee shops are not the olympics. You are stretching this analogy beyond its usefullness.
> I'm surprised this idea is novel to you.
Could you possibly express your thoughts without putting down others? Thank you.
To address the meat of your comment. It sounds like you are proposing to grade the baristas working the bad shifts and the good shifts separately in different "leagues". The problem with that is that assumes that you are aware of all the factors which form the different leagues. If there are clear "night time" vs "daytime" barista groups that works. but if you just assign baristas as scheduling works out then you will realise that some people (randomly, and through no fault of their own) will be assigned to the slower shifts. Will you fire a perfectly good barista who is meeting the expectations of your establishment just because scheduling worked against them in that evaluation period? That is what stack ranking did in the case of microsoft.