There are any number on exploitative minor practitioners, at least three in Chicago raised up by Cowl that we know of. Who knows, Cowl may have been generating an entire network, which included BOTH Gregor and Aristides. Certainly a hold over a Dragon would appeal to Cowls long term plans and be very much his style via Gregor. Siriothrax could have blocked Ferrovax in Battle Ground for example.
Aristides on the other hand was suddenly able to get the weapons to attack Murphy and her little band (information Nameless would be aware of) when they proved effective against Listen’s operations. He was someone completely outside Marcones operation capable of performing a hit on allies of Marcone.
Not the same person, but the same type of person both working for Cowl/Nameless in a similar capacity, for the same end. As a lawyer Nameless can keep them under the radar of local law enforcement, as Cowl he can keep them under the radar of the WC, but not the WG or Harry: