Hi Todd,
I've read to post on BGG and I agree with users that consider "Counter Attack" as the ability to use "the same card" the opponent just played.
So every resterictions are "reset", and the player that used "Counter Attack" can activate a different number of units than his opponent (if available).
I consider it as a
Clone Card, the only limitation is the section (in case of Leadership card).
I think you can find a FAQ
here
, under
Counter Attack section: question 3.