[Tknl]

I usually see this style from people with a mathematics or physics background instead of CS. Their coding style doesn't take maintainability or collaboration with others into account. And these programmers therefore produce code which no one else is able to change when they inevitably leave the company after some technical strategic direction change happens which they disagree with. Allowing them to dictate your coding standards is putting your company at risk. If getting them to confirm to (tooling automated linter) coding standards is impossible I'd personally isolate their code to specific packages with clearly defined interfaces so you have some hope of replacing it after their departure. Make a working agreement with them that coding standards apply to any PRs outside of their pet projects or they'll get rejected.