I'll start out by saying that I'm not a mind-link hater. I think its a cool ability with a built in downside and it fits the EU lore surrounding manaroo and her race. I think the problem is that you can link an unlimited number of ships so the action economy to cost ratio goes up exponentially.
With the benefit of hindsight we can say that maybe it should have looked more like this:
Manaroo (1pt) Unique Crew
Whenever a friendly ship equipped with the "Attani Mindlink" upgrade performs a focus action, you may perform a free focus action. If a friendly ship with the "Attani Mindlink" upgrade receives a stress token, you also receive a stress token if you do not have one.
Attani Mindlink (1pt) Unique EPT
Whenever a friendly ship equipped with the "Manaroo" upgrade performs a focus action, you may perform a free focus action. If a friendly ship with the "Manaroo" upgrade receives a stress token, you also receive a stress token if you do not have one.
This inherently limits the number of ships that can mindlink to two, thus limiting exponential action economy. It also requires one of the ships to have and use a crew slot. Secondly, it also changes the 'assign a focus token' text to 'perform a free focus action' which allows Attanni builds to become more vulnerable to stress.