I have a theory, Yusuf Tazim is Malik's descendant 1. If his name if westernized, it is Tazim Yusuf. tazim was the name of Malik's son. 2. he shares a rivalry with ezio, malik shared a rivalry with ezio's ancestor, Altair. 3. he is a master assassin, just like Malik. 4.He is second in command compared to Ezio. malik was Altair's second in command. 5.They are both Bureau Leaders. Due to similar Positions, name and Persona I have to belive he is Malik's descendant.
just my theory, but It makes sense.