I don't think it's really meant to be a Great Silence 2, but Françoise Fabian actually was a good friend of Jean-Louis Trintignant, who advised her to take the part when it was offered to her. The bullet proof vest most probably is a remainder of Corbucci's/Van Cleef's original plans about a warfare specialist (and so maybe is the title, at least the French one). Still, it's not completely impossible that Corbucci is referring to The Great Silence; it might be a joke, something like: this is what Silence should have had (and in the happy ending he has something to protect his arm, if i'm not mistaken). Like I said in the review, Hud is closer to Silence than to any other protagonist of Corbucci's movies, that's maybe why he chose a French actor again. It also secured him of a hit in France, because like I wrote, Halliday was and is an incredibly popular artist in the french speaking world.
And the Pollicut thing? I don't know, I noticed it, but if it was deliberate, I guess it's a kind of joke too. I don't think the name 'means' anything; as far as i know it's not the name of a famous banker, or something like that. But you never know.