: I don't have any specific belief as to who it is, since
: he's apparently not the faceless man
I never said he WASN'T the Faceless Man, just that there's nothing that says "The Head is The Faceless Man". I know who the Head was in life; your evidence could very well be used to support him being The Faceless Man in death.
: Anyone else i'm missing? Tell me!
Yeah, the simplest and most plausible explanation: he was a former advisor/lieutenant/avatara/whatever of Connacht's, who was beheaded by "Balor" (which could either mean Connacht-as-the-former-name-of-Balor, or The-Leveller-who-would-later-control-Balor, ie Moagim, which is who I would place my bets on).