I have worked for an existing small, tech/dev company as a senior employee since the companies inception 2 years ago. A month ago we hired a new junior employee. He's a good worker so far, but I've realized he's got a lot of dogmatic standards about his programming style. We've got a well established code base, and at first he was making blanket changes to code styles without asking, leading to further discussion as to why. The blanket changes have stopped, but the aggressive discussions and pushing has not.
We've had a few good discussions on how to improve the quality of the code base, and some of his suggestions have been implemented to improve things after discussing. However, he is quite dogmatic, and seems to refuse to accept that any of his ideas could be declined. In some cases, as the senior project lead, I've not agreed to accept a major project wide ruleset.
My reasoning is often that I don't agree that his changes improve things for the better, and having such a strict ruleset doesn't create positive results for the team. It creates a level of unneeded code management. Usually I suggest adding it to a list to be regularly reviewed later. Some examples of his suggestions are removing every bit of commented code (code that needs comments is poorly written?), removing line breaks he deems unneeded, as well as curly brace positioning.
What I get back from this new employee is aggression as to why I wouldn't accept this. His reasons are past projects that implemented them, or reference to some Google standard that may suggest them. He points to a book he respects. I do not believe every piece of code needs full regulation if well written. I've got plenty of architecture goals for the project, but less have to do with spacing, line breaks or removing code comments.
My question is how to work with this new junior employee as an existing senior employee? It's a small company and everyone is mostly a peer, but I'm his advisor to the project, and have been leading it for 2 years. I've brought it up to the CEO who has suggested a group meeting-- but I feel like this is becoming a matter of whoever speaks loudest the longest wins. More regulation is not necessarily better.