“I thought that I could instruct him just as well as Yoda. I was wrong.”
This quote would make more sense if he said Qui-Gon, clearly, but we’d have to establish somehow that Luke knows who Qui-Gon was or else it’d seem odd that he didn’t ask. Putting the name Qui-Gon in “was I any different when [Qui-Gon] taught me” in ESB probably helps this a bit but it still seems odd.
I don’t have the biggest issue with that line, personally. Easy to think that Ben could have swapped in “Yoda” there for “Qui-Gon” or “Mace Windu” or whoever, but decided to use Yoda because Luke was familiar with him.
Arguably, with the PT in mind, the line meaning now is essentially that he was arrogant and thought he could train Anakin as well as the greatest Jedi teacher there is could.