No, you are right, there is no way to verify
The only thing we have to go on is the absence of people in the sim and them all having the same names (see OP).
This, to me, is evidence enough when going to sim after sim and seeing very few people in them. Something is disrupting the 2nd life search engine, because there 'are' people using public sims yet doesn't seem to find them.
A red herring if you will, and I'm just interested in people's thoughts on the matter.
It's annoying that there are no easy ways to find people in second life. In place of a hard method, there are a number of half measures one can take that have a very small percentage of sucess.