I searched the forum and see this has not been discussed. In episode 08, 1:48, the fisher hollow person sys "I will go" and several other, humanoid, hollows are present. Given how they land, and the fact that they have a more humanoid form, I am guessing they are the equivalent of hollow captains.
Now consider that later in episode 9 2:45 the hollow claims to have no previous memory of Ichigo: its not personal. Then finally towards the end of that episode (17:35) it mentions "beaten by a mere death god?!". This suggests (and supports the above) that there are things out there that are more powerful than the most powerful, active I suppose, death gods.
The connection to the overall plot is a weaker, but may very well fill in in the next few episodes! It's been theorized that Ichigo is actually part hollow himself, and the pale Ichigo he fights for his soul slayer is perhaps a representation of this. What if (drum roll) the hollows have a goal and are somehow connected to/in control of SS? Given there is no obvious motive behind the death sentence of Rukia, except perhaps pure chaos.
Given the variations in hollow powers I think its concievable that some hollows would ahve the ability to blend in with death gods etc. Anyways, discuss I suppose. I think this is a topic that hasn't been looked into much, ie the plot from a hollows perspective in terms of goals. Remember that there clearly is some type of structure, or higher ups, among hollows.