There's no real winning these on a point by point basis because the entire system of wage labor is set up to separate you from the value you create for owners as much as the market will bear. Employers agree with this openly every time they talk about how this is a market, though they avoid the charged language and obfuscate it by drawing focus to other ideas.
These kind of logical points from employers are not rules or based in any reality except for ones where they simply have power over you to suppress your pay. Hence why these "rules" shift over the years as standards shift in favor or away from workers. These are among myriad tricks for fighting a class war against labor and maximizing extracted value. The best way for workers to beat these pay systems is to apply organized pressure collectively, not for you to have a private conversation with your boss or HR.
These kind of logical points from employers are not rules or based in any reality except for ones where they simply have power over you to suppress your pay. Hence why these "rules" shift over the years as standards shift in favor or away from workers. These are among myriad tricks for fighting a class war against labor and maximizing extracted value. The best way for workers to beat these pay systems is to apply organized pressure collectively, not for you to have a private conversation with your boss or HR.