Posted By:
Joe D.A print shop can have more than one press.
So, more than one form can be run at one time and then sent to the cutter.
Also... letting a job dry before cutting (a whole day or over a weekend) is not all that uncommon even today. If you coat a job, you can cut it right away - but I don't think they coated T206s or any jobs back then. If I printed a sheet of cards without coating, I would definitely wait a day (or maybe longer) before cutting.
Some colors don't dry as quickly as others... sometimes there is a problem with a sheet from the mill where the ink doesn't soak in good... sometimes the formulation of ink can be bad.
There are a whole bunch of "sheets" reasons that would account for a different player ghost on the back of a card.
edit to say: John beat me to it.