Upvote:9
Arians were not underrepresented at the council of Nicaea
Arius started saying that the Son was distinct from the father under Alexander of Alexandria, so it's probably in 313 or so. So Arianism was less than twelve years old at the Council. So the reason there were so few Arians on this council was that Arianism was a very new thing, not that they were underrepresented.
At the council of Nicaea there were a few bishops who supported Arius position (Warren Carroll claims 22). But they didn't prevail, and the two you mention are the only ones who preferred to be thrown out of the church than to sign the Nicean creed. (Source: Carroll again)
Your further comments and claims about there being many Arians are first of all not evidence that Arianism was widespread. It's just points out some notable Arians, but it says nothing about how widespread it was.