Wolf seems to think that young R’ Tarfon would have read his name in a mishna before he himself aid the “opinion”.
The way I understand it is that R’ Tarfon learned the “opinion” from his Rebbeim, they obviously did not say it in his name as he had not yet said it. He then taught it to the next generation and it was therefore written down in his name. Why it was written in his name and not in the name of his Rebbeim is another question, I assume that R’ Yehuda HaNassi was quoting R’ Tarfon directly and therefore R’ Tarfon got his name on it even though R’ Tarfon was quoting his Rebbeim.
How machlokesim came about is another discussion. We say Eilu v’eilu, it seems that 2 talmidim each interpreted the same teaching in different ways and they are both correct.