The declaration of the Trinity from the Council of Nicea was not coerced by Constantine, it was made in opposition to Constantine. The emperor sided with the Arians, denying the divinity of Christ and treated Him as merely a created being. The Christian understanding of the Trinity stands completely opposite to the heretical Arian understanding and thus Emperor Constantine’s at the time of the council, though I do believe that he ultimately accepted the decision of the council. It was another couple of centuries until Arianism completely faded away and it still pops up from time to time.
Your history is wrong, thus the rest of your statement is baseless.
He's learned from Joseph Smith; so...