You know, the victors write the history. The violence went both ways. E.G. Valens successor Theodosius persecuted and banned Arians for a change.
But, mostly, the discussions were between Church Fathers and probably quite civil. Arius himself participated in the council of Nicaea. That means, he was at least respected to get the invitation. There were even Fathers who tried to somehow find the middle ground.
Arians got it posthumously. After they disappeared, the medieval Church historians really went after them and smeared them viciously.
To this day, they are getting the bad wrap.
My main point is, Church had several major “discussions” in its history(see e.g reformation) and the losers were often portrayed as devils incarnate. Most of them were honest people, having some unorthodox views, sometimes quite obscure and in hindsight sometimes quite irrelevant.