It’s not an argument, it’s the entire reasons wage structures exist.
There is a tiering of players and it is established as to what it means to be the best player, a top player, a first 11 player, a squad player etc, and also probably weighted depending on position slightly.
If we make Toby the highest paid player, you’re going to get Kane and Eriksen justifiably asking for parity as minimum but more than likely more, as well they should. And the scale will have increased for every single player in the squad. As people say, Sissoko is probably the only one that wouldn’t demand a rise because he’s been used as a squad player but signed on first 11 wages, so he’s probably been earning 30-40k too much per week on his basic (although before this season wouldn’t have made the bonuses for playing that others would). Every other player would also want a rise, less they be paid 1/3rd or 1/4er of other players in the squad which isn’t how the balance has been established.