Pin as a mechanic just isn't interactive at all currently: only two cards in the game actively remove pin, Rally and Desert Push. Most cards countering pin are passive, i.e. units which cannot be pinned. Aside from being very niche, these units are also very static and uninteresting.
This results in a game where the person whose units are pinned just has to wait, whereas the opponent has many flexible and cheap pin synergies. no other unit-based mechanic is this uncountered.
Back when pin was a less common mechanic I can understand not having many counters, but now that pin and cards conditional upon pin (especially cheap hard removal through sonia and surprise attack) are much more common, i think it is time for other nations to get pin counters as well.
I'm not saying pin counters should be generally useful in all situations; its just pin is incredibly frustrating to fight against right now. If i face a game mechanic and decide i want to change my deck to be more resilient against it, i should be able to do that. Adding orders or units that remove pin or give benefits if pinned can help do that.
Alternatively, just reduce the amount of pin cards, or spread them out between multiple nations!