For a theater setup I use two C920 Logitech webcams (they have a very good quality and almost no delay) with Resolume Arena 4. The program recognizes and shows me 2 webcams of the same type in the sources list but i doesn't matter which I drag in the clip container - I always get the same stream (it only can adress one of the streams or it list 2 webcams but use the same stream for both of them)
By now I found a workaround: I process the 2nd camera through MagicCamera, in which I can choose it as input and it will be rerouted to Resolume through MagicCamera source clip.