I liked Brownbeard sudden appearance as it actually answered a question of mine, could anybody from the Military be in charge of going around and trying to take some of the land WB was protecting ? I mean maybe thats what M and Law are doing taking some of that territory for there cause ? Although the only problem I can see is it doesnt suit Law personality.
Brown beard was presumably taken down by Hawkins. So unless Hawkins lost, which is very doubtful, Law had nothing to do with it. It could be that Hawkins is the last SB, and turned in some pirates ( Brown beard being one of them )
to the WG
Given that there are frozen prisoners on PH, it wouldn't surprise me if Law had access to criminals.