Even if it’s true it’s not a good argument. You deserve to be paid market rate and if other people in the department are willing to settle for less, that’s their problem.
Just tell your manager you need a moment and want to go see how much your coworkers make. Then go to your co-workers tell them how much you make and that you want a raise and ask them how much they make.
I generally tell people at jobs how much I got hired for within 2 days of joining a company.... there are no down sides.
There are plenty of downsides if your pay is higher than someone with seniority because they aren't gonna like the “new guy” being paid more. Then that will cause animosity between them and their boss for bringing in outside talent instead of feeding the mouths he already has. Then your boss will be annoyed with you for already creating a headache in your first week
I generally tell people at jobs how much I got hired for within 2 days of joining a company.... there are no down sides.