Everyone collects the set differently. From the way I see it, it is impossible to complete a "full set", as there are simply too many variations. It would be interesting to see all 60-80 scans of Johnz28's player run, to see just how many variations he has between the two poses.
I assume that some people consider these two cards to be the same card. An "0126" or an "285-1". In my mind, these are two completely different Mack Right Hand Held High variations.
The pose number is helpful in communicating with other collectors, because they either know 285-1 is this Mack pose, or they can quickly look it up. Just like people understand what I mean if I say, "Park in the driveway", or "Drive on the parkway".