PhD students are typically more knowledgeable than the PI, so this is probably optimal. Perhaps a good Postdoc is better. PIs are often way outdated in their

PhD students are typically more knowledgeable than the PI, so this is probably optimal. Perhaps a good Postdoc is better. PIs are often way outdated in their knowledge and don't have the time or energy to stay abreast the developments in the field. That's what PhDs are for - they have to prove themselves in developing what should be their most important work of their lifetime before switching to what is essentially management, rather than science, unfortunately.