1991 UD Hologram errors

For whatever reason, 1991 Upper Deck's base set came with several different holograms on the back of the cards. Ranging from the standard 1991 Upper Deck hologram, to the previous year's 1990 Upper Deck containing a repeated pattern of baseballs, very oddly 1990-1991 Upper Deck NHL's design with "90" and crossed hockey sticks, as well as 1992 Upper Deck's design. I'm not sure where each of these come from, I would hazard a guess that they're obviously from different print runs, but why would they make these errors? Chase $$$? Confuse collectors? Strange times were the 90's...

I recently broke down ~10,000 cards from the set that were thrown in 5,000 ct. boxes by my LCS, and pulled all of the Twins. Here's my breakdown of what I found:

Make of that what you will, but I find this kind of rarity breakdown cool. There is also apparently some with the Comic Ball 1 hologram, but I didn't see any of these in what I went through. Also, I wasn't looking but I did find a Rangers card with the 1992 hologram, #191 and a 1990-1991 NHL hologram for #666(spooky...). These are all from 1991 Upper Deck, with photos below.

75 regular 1991 UD designed hologram cards.
23 1990 MLB UD designed hologram cards(1x#167, 2x#170, 3x#360,  1x#377, 8x#501, 3x#503, 4x#505, 1x#659).
16 1990-1991 NHL UD designed hologram cards(8x#360, 5x#377, 2x#659, 1x#698).
1 1992 UD designed hologram card(1x#490).

Poor picture, but this is 1990 Upper Deck. Baseball's that rotate back and forth are most prominent, but I think I see a '90 also.









1991 Upper Deck regular(left), 1992 Upper Deck regular(right). Very odd that this would come out on a set released the year prior, no?

This is 1990-1991 Upper Deck NHL edition. Repeated pattern of smaller '90' in the background, with hockey sticks crossed.

Editing to add, I found one among my dupes, that doesn't match any of these, and seems to match the Comic Ball Series 1 hologram! This one almost looks like the 1990-1991 Upper Deck NHL design, but the '90' in the hologram is much bigger(in person anyway...).