Shemar, I wouldn’t look at things in this way. The cards you have are playable, the game worked before and it was not broken.
They came to a cross roads and were faced with a decision. Do you continue to make new sets playable with the old sets knowing that improvements could be made to the old sets and in doing so you would not incorperate improvements to these new sets?
What I feel they tried to do is fine tune the game pcs and rules to make more units usable and elimate the far superior units. Also they attemped to make game play more realistic.
Again the old cards are still good but the new cards and rules should improve things (I HOPE). We’ve been through a similar circumstance once before when they resized the units. I still use my old units, looks stupid but…