Most of those stoppages you are only seeing the point the ref jumps in when you dont see the preceeding action it does look early but the Veit and Woodhall fights, Joe was manhandling them and dropped them to the point where the ref could see that Joe was just gonna keep pumping out the punches.

As for Manfredo the twat did that to himself by not fighting back. Ok he wasnt taking many if any punches but he wasnt showing any interest in fighting back and as we now know, Joe could have kept the pace up for a long time.