I haven't even found that much reason to use counterspell or even have Gale use Shield at all because there were so few spellcasters with actual threatening spells or anyone actually targeting Gale.
not sure what you did differently (are you sure it was tactician?), but for me the enemies targeted gale *fanatically*. as long as he was detected, they would forget anything else and try to kill him. i ended up having him sit out most fights outside of combat, occasionally re-summoning connor, casting distraction cantrips, and sometimes concentrating on something.
