Comment by brudgers

Work that requires coordination of independent schedules takes longer than the theoretical minimum.

It's a queuing problem. See: https://www.johndcook.com/blog/2008/10/21/what-happens-when-...

The slowness of processes that involve other people will frustrate you until you realize it is an ordinary part of the work.

My advice, is behave in a way that makes you the kind of person other people will want to work with. Turn your work around quickly. Be patient with other people's turn around time.

Good luck.