Let us not quibble over the exact number of Protestant denominations. There is clearly division and discord among those who call themselves Protestant. If not there would be no need for the various denominations.
There were clearly divisions in the early churches. They held councils to root out heresy. The creeds were created to clearly outline the necessary belief to be considered orthodox (right-glory) Christians.
Creating the creeds was not easy or straight forward. If you look at the content of the creeds, that was the entirety of Christian unity. Outside of these creeds, there was a wide variety of traditions and beliefs that they could not reconcile.