Zainab was awesome, but I don't think the family particularly needs her. They just need a story that will give them direction. I think there are snippets of story here and there, but things either never really progress, or they last an episode or two at best.
I hope they dedicate the same amount of screen time to Shabam's supposed secret, as they have done with the Carters and, I hope they develop the Tamwar/Nancy thing into something with meat, instead of it just fizzling out. Mas is the only one without a story, but if he's involved in his children's stories, then that might not be so bad - anything that develops them as a family is welcome.
On a side note: I think they've missed some opportunities in not giving Mas/Alfie more scenes, especially with both the families history with fires. Mas should have learned that Alfie set the fire after overhearing an argument between Alfie and Stacey, and wrestled with that knowledge for a while.