In my opinion, Martin, Turnoi, John O Shei, Sludge and the ubiquitous Silverboy are all individuals.

Oh, why do you think that then?

Sludge seems to be sincere. SB is definitely SB, when de doesn't uses a different handle. However, Martin, Turnoi and O'Shei are all the same person. Now you probably think that Turnoi's level of English is not good enough to be the other two(numerous others also) and that's why I compliment him on the hard work put it copying and pasting.