Shame this was the only time the two really spoke to each other.

Per Linwood's words, he's always been a fully fleshed out character based on his older brother, intended to be in the show for the long run.

Yet, I've even seen people say that Malcolm was only supposed to have two brothers to truly be in the middle when Linwood also says, in this interview, that it wasn't even the original title of the show.

Source : The Yes No Maybe podcast