Yes, I think it's possible to correlate two identities just using stylometry. Or at least it would be sufficient to shorten the list of possibilities significantly. But I also think this is something that (at this stage) only a highly skilled/motivated adversary with considerable resources would do (such as a state agency). And I also guess this depends on your "original identity" being "talkative" online so that the correlation could find something to correlate to. I don't think my guide is paranoid enough to protect fro such adversaries as for instance Tor itself made it clear in their design paper that protection against a "global adversary" is not really intended. In my case, this seems "out of scope" for now and above the threat model of my guide.