We will have scammed PSG big time if doing so.
Hernandez is a decent player, but he's just made of glass - at best. And to be fair he never really made a difference here.
De Ligt made a way bigger difference in 1 year than Hernandez did in his 4 years here. Some Bayern fans says that he's our best defender when fit, but I simply don't buy that. De Ligt as a pure CB is definitely better. Stronger, taller, better at heading, tackling etc.
Hernandez might be quicker, but that's it.