Eliwood: Generic FE Lord. Red Hair, uses Swords, Anima Element, special weapons are Rapier and Durandal. Stats are well balanced, personality is pretty generic "Nice guy and heroic" type thing, etc. Also originally a Japanese character who was an NPC.
Sir Robin, the Not As Brave As Sir Lancelot: Humorous character from Monty Python and the Holy Grail, Red Hair, played by Eric Idle, origin of movie is Brittish, uses swords, completely cowardly, holds a shield with a chicken on it, does not know the capital of Assyria.
...yeah, ok, basically, the only connection I see is "Swords" and "Red Hair." And Robin's Red Hair could just be me thinking oddly. Also noteworthy that OK has a low opinion of Eliwood (hence "Elitard") and it seems like everyone in this is some sort of hatable character in OK's eyes one way or another, and...yeah. Though, I figured Eliwood would be a Scum given how much he opens about hating him, but I guess Evil is reserved for the people he absolutely despises (I wouldn't be surprised if, say, Alicia from VP2 is Scum, for example.)
Frankly, the two are...not a like at all. I see really no connection whatsoever. It'd be one thing if Zenny claimed, say, Justin from Grandia; at least there we'd have 2 RPG Main Characters with Red Hair, who I don't think OK has a less than favorable opinion of (I think?) But...yeah...
...on the other hand...hmm...thinking about it...
There may be one connection the two have that I just realized:
Nobility. Knight of the Round Table = Sir Robin, Eliwood = Noble Lord. If I'm right, I think this is going to be divided where Good = Nobility/Royalty/etc. and Bad = Not. Its a shakey connection, but its there; note that the only other revealed person (and this is assuming Zenny did in fact reveal his role name) was Shion, who does not fit that connection.