Not to mention Ysayle's farewell performance at Azys Lla all but ensure that Garlemald would actually want to kill the Civilians, lest they summon primals. In the Othard sacking, They likely saw the casualties as collateral damage, a "necessary" sacrifice for their crusade. Now? The casualties would become the goal. In Garlemald, I'd expect propaganda popping up portraying Nael as the perfect commander instead of a rouge agent in light of this, as well as them planning ways that will succeed where Project Meteor failed.
