They were very knowledgable about the document they'd helped produce and knew all the reasoning of the convention and the Framers, but at the end of the day, they were still advocates for a point of view within the convention, from which almost all the people who disagreed with them had either been excluded or had decamped in disapproval.
Furthermore, The Federalist does not deal comprehensively with the Articles of Amendment demanded by the Antifederalists and public opinion: and it was here that Madison, I read in The Antifederalists, began to see the dangers to personal liberty and the potential strength of the government he had helped Hamilton create, and began his migration over to the Democratic Republican ranks, taking some Federalists with him.
The Amendments of the Bill of Rights substantively altered both the content and the nature of the Constitution itself in ways demanded by the American people before they would ratify it, and the Federalists acceded in order to get the document agreed to.
As amended, the Constitution contained many more safeguards and many more points at which power of perpetual consent was distributed back to the People in the jury box, the polling place, and the ranks of the Militia.
And it reserved all nonenumerated rights and powers not specifically granted to the United States Government to the States or to the People. Which is precisely what you National Greatness power junkies and your liberal pals have been trying to break down ever since, to make the People your prey.
You are misstating Madison's view of the necessity of the BoR. He sheparded it through because he had implicitly promised to do so and did not believe it necessary. Most of the Federalists did not care if it were added believing it would not substantially change the document. They had what they wanted and saw no reason to further antagonize their opponents.
And, no, the Anti-federalist view was not one based upon understanding the document if it propaganda can be believed which raved on about "monocracy", "Aristocracy", and threats to Liberty from standing armies. Absurd stuff that any rational man would be ashamed to claim.
As the quote from Madison posted to you by another he clearly stated that the 10th refered ONLY to local police powers and regulations. Matters outside federal power.
A failed thesis if there ever was one. Madison was the primary author and shepherd of the proposed amendments in the 1st Congress. He let nothing in that "substantively altered both the content and the nature of the Constitution." The Federalists were in firm control of the 1st Congress and they were not about to undo their recent successes.