All "XYZ Format (D)" decks are meant to be played against other "XYZ Format (D)" decks in my deck lists.
The "A" / "B"/ "C" etc. for each refers to different formats, so those decks are from the same era and play fairly against one another according to a common ban-list. Decks from different formats can be played against each other, however, just wont be perfectly fair in terms of ban-lists and cards that were out at those times.
These were all made off meta deck-lists from that era, but were made to be played casually with friends to remember the good 'ol days.
Enjoy!