Actually the general belief is that Souter was pulled to the hard left through his companionship with Brennan. So perhaps that would be a more specifically applicable analogy, but the point it conveys is still the same.
Marshall and Hamilton were the greatest legal minds of their day and likely any other.
Not really. They were good but not the greatest ever. They are both dwarfed by Blackstone, among others. They are also surpassed when one considers law through areas of legal specification. The legendary courtroom greats like Felix Grundy and Luther Martin come to mind in that realm. The philosophical lawyers like Lysander Spooner and to some extent St. George Tucker classify as the greats in another realm, and so forth
Luther Martin left the Convention before it ended and did not help write the constitution.
Martin was present throughout most of the major debates and is generally credited with ensuring that the Senate had equal representation for each state - a provision he inserted into the committee compromises that led to the design of the senate. He departed late from the convention in protest to prepare to fight it in Maryland. Throughout the summer he was one of the most frequent speakers in the general session per Madison's notes.