Different optimizers for generator and discriminator in GAN

I've seen an advice about GAN implementation, that there should be different optimizers for generator (G) and discriminator (D). As I understand, it depends on how fast each model (G and D) convergences. I'd like to clarify this question. Why is it possible to say, that, for example, GSD has to be chosen for D and Adam for G only and not vice verse? (Intuitive or mathematical explanations are welcomed both)