You've got to like Apollos! He was powerful in the Scriptures and eloquent. He "boiled in spirit." He had heat, but not quite enough light. He taught accurately. . . but needed help to teach more accurately. How great that those two mature saints cared enough for God's church to help him. In the end, he refuted Jews in public debate, showing from the Old Testament why Jesus was the Messiah! Yeah!
What grace to one church -- Paul stopped on his way through, Apollos spoke clearly, Priscilla and Aquila moved there, and then Paul ended up staying three years! God had particular interest in this church (Revelation 2:1-7).