I haven’t written a full story, but I have written summaries before! When I have a little more time on my hands, I may push through to some more episodes before finishing Some Enchanted Genie.
I think because they’re background characters, the animators didn’t expect people to notice, but when you’re watching closely, it sticks out. It’s possible that some of the people in the Forty are longer-remaining, veteran members – the ones they didn’t arrest in the raid, and others come and go. It’s even possible that Abis Mal tried to strike out on his own and somehow managed to convince a few people to come with him. Maybe he didn’t much care for Cassim’s all-noble tactics and there were a few that agreed. Given Cassim and Abis Mal’s shared interest in treasures with a magical bent, the idea that they collaborated and parted on less-than-positive terms actually makes a lot of sense.