Honestly, the main cast has been pretty much been marginalized to make way for all these Marley actors. Like with Armin attacking the dock, Mikasa's only real moment to be Mikasa was when they were fighting there, too. Since then, it's been way too much Gabi being an ignorant shit with not enough Levi curb stomping people in absence of the general titan threat the series started with. It's just that common manga/anime curse of making too many characters with limited potential screen time as a result.