Agree with them on what, exactly? Grace?
There are giant swaths of Augustine's writings that I am not sure how any Calvinist could read without twitching. He wrote quite a few sermons celebrating the feasts of the martyrs for instance.
You have to read them in order to understanding Augustine Christian evolution. Once Augustine understood that it was by grace he was saved, he recalled some of his works to be burned. This is written in the final writings of Augustine.
Augustine came to understand that we are saved by grace and grace alone. He championed this through the Council of Orange decrees to fight against Pelagius and Semi-Pelagius. The Council of Trent has ignored the Council of Orange’s decrees favoring a Semi-Pelagius view (though they will deny it). The synergistic view of the Council of Trent all but ignores the early church father’s writings.
Shall I point you to some passages in the Catholic Encyclopedia that states the church fathers were mistaken, didn’t fully understand, etc.?