jraines mostly got it. It's worth noting the look and feel of the Sachs studio. I doubt anyone is taking that advice completely seriously. But if, instead, you just said 'have fun, do whatever!' things would probably be a huge mess.
Source: friend worked in his studio.
An important part of finding this balance is deciding exactly how much you trust your underlings to know enough about what the hell they're doing so that they don't do anything dumb, and to have a vision closely enough aligned with yours that their attempts at improving your ideas usually make you delighted. Clearly Sachs is not willing to extend much trust to people he is just now hiring to work in his studio.
Like, would you be happy with an intern fresh out of school who decided to roll their own crypto instead of interfacing to the library you told them to?
It's not a good situation but it's standard among big nane artists (Koons is notorious for strictness, afaicr)