Let's see... suspicious amounts of newly created families with homes conveniently located in Storm's Keep/Storm's End, and later on in Valkyrja/Yggdramir... hm, you're right, no idea why people would think there's an OOC clan.
Because they lack creativity, and OOC Clan just so happens to be the laziest, and thus easiest conclusion to go to? Most of the family homes in Storms Keep, were manually moved to Storms Keep, when it became obvious our regions were obscenely poor by the standards sert by just about every other region in the game, I was going to move mine as well, till I ran out of time. As for suspicious amount of new characters, are you taking the piss? Look at Sirion, look at Astrum, or Morek Empire, Thulsoma had a tiny percentage of new characters, and especially compared to the amount those realm get on a regular basis, Sirion imparticular, but when we got new characters, which was incredibly rare (I swear we got like ... 12-14 throughout the entire war) we made the effort to ensure they enjoyed the realm enough to stay, and of course, who wouldn't want to join Thulsoma? Our capital is called Storms Keep and we always had high levels of glory, which several have admitted was the main reason they chose us to go to straight away. I mean, compare Gaston, or Eidulb to Storms Keep, one name is obviously better and more interesting than the other, and so players will be more inclined to join one than the other, that said, by my marking, Astrum got many, many times more the number of new players (Which, I am sure is largely accountable to many more duchies they have)
Only a small amount were actually OOC Friends before Thulsoma, and most of those were friends I made in other realms, others became OOC friends in the progress, as anyone can tell you I'm notorious for OOC conversation with players.