I'd agree the show isn't quite handling its full range of characters all that well, I blame running out of season at the moment.

Obviously at somepoint we'll have a sub-arc about Aqualad and Black Manta but I can see at least here why it wouldn't want to start that right now, and with him firmly in confident leader mode its doesn't leave much.

I'm less favorable to new additions getting no focus though. Zatanna is being played as having lost her father which is always serious drama, but is essentially non-existant. WTF?