I agree that there are a lot of coincidences; profanity in the usernames, similar coding style for the two sites, similar business models, similar administration... but again, non of that is irrefutable evidence.
Whether or not the evidence is strong enough or not--which it seems to be, and I would definitely believe these are alt accounts--the main question in my mind is whether any DT members would act on this information or not. Merit abusers generally don't get tagged anymore unless the abuse is extremely blatant, though I can't speak for what Vod would do. My point is that most of these threads that purport to catch alt accounts sending merits to one another are just wasted time & energy, because the outcome is usually that the accounts don't end up with any tagging whatsoever.
I think threads should only get started when there's extreme abuse going on
and when the evidence that accounts are linked is very strong. Neither of those things are the case here, but I would certainly be interested in what others have to say.