Brutus Brain + Rhoa mount + Minion Pact II

Hello guys, I have seen in many builds that they use Brutus Brain on their Rhoa mount, and Minion Pact in their skills (Lightning Arrow, for example). Brutus Brain says in its description that the minion takes no damage, but Minion Pact needs to damage the minion with a % of your maximum life to grant extra damage bonuses. My question is, should I remove the Brutus Brain gem from my Rhoa mount to make it possible for the Minion Pact gem to work?