Rabbi Soloveitchik contends that the Lithuanian rabbis were not great orators. He said that Rav Chaim Soloveitchik was a great educator but only spoke publicly twice a year.
Rav Elchanan Spector gave the same speech every year for Shabbat Shuva. He would say, “We are foolish and have committed transgressions.” He would then break down and cry uncontrollably. The congregation wept with him. Moshe Rabbeinu was a stutterer. These rabbis were able to influence because of their moral character. People could feel their sincerity.
Some of our greatest rabbis were not great orators. There are moments that an impassioned speech can truly influence. Ezra Hasopher made one of the greatest speeches in history. He was able to convince Jews to divorce their foreign wives.
Even though Ezra did make a great speech, the effect came because of his righteousness. Words alone are not what influences. It depends on the moral character of the speaker, that affects people.