Ok, young Vito sits at the table with Clemenza and Tessio discussing how to not pay the $200 bux.

I'm confused. I'm assuming Abe Vigoda's Tessio is supposed to be the same Tessio at the table with young Vito (considering Brando and Vigoda are both of a similar age in the movie). But who is Clemenza? Is Clemenza who makes the spaghetti sauce and meatballs the same Clemenza that was sitting with Young Vito (the one who stole the rug with him)?? Or is he his son?? Cause Clemenza (who makes the spaghetti) doesn't seem to be of the same age as Brando and Vigoda (Vito, Tessio)

This is driving me crazy. I'm new to the GF movies. I've seen them about 7 times each and I'm still catching on.