Is the level 2 of that building supposed to be a one time bonus to the units you have out or a persistent effect? As I would've imagined it would be persistent seeing as you have to dedicate two more Urchins to get it, but it runs as a one time bonus? Just curious if this is the intended design.

[Edit] Weird, I just played another round where it played persistent. Either I lost an Urchin in it during that game and didn't notice, or for that one game it didn't play persistent powerup.

It's persistent - though there's a bug in the current build where subsequent gangs won't get the health bonus when recruited. That is, when you get Strangefellows 2, all existing Thugs and Gangs get +1 health (and +1 to their max health as well), newly-recruited Thugs start with 2 health rather than 1, but newly-recruited Gangs do _not_ get the additional health that they should be. This will be fixed in the next build, which will come out later this week, once it's gone through QA!