I think the distinction is more that pre- Washington the position didn't have much power. Washington was the first Commander-In-Chief. His role there overlapped Pres 10. Because of that ceremonial aspect, I suspect it is more of a case that the position gained radical powers after the Constitution was put in place (edit to add: And became the office we see today).
Really, the Pres before that was more of a cheerleader from sounds.