From what I have seen with my guys communication between Ugobes is also pretty random. They don't always talk to each other, more often than not they just walk off in different directions
but they will sometimes have a little honking session and once they even sang to each other
They do say hello to each other but this is also pretty random.
If I were you I'd go for the rb. It is an experience that is well worth it. You can then always add another ugobe to your little herd later down the track