I really like the behavior associated with defend orders on ships, but the system for automatically assigning ships to defend orders is pretty clunky for that purpose. I want an order that functions like an escort order for the purpose of assignment, with the ship behavior of a defend order.
An example: I want to do things like have a group of frigates defending a lead frigate without bigger/slower ships getting assigned and trying to keep up.
I can usually achieve what I want, but I often have to spend lots of time reassigning/manually assigning ships to get what I want, for instance I have to manually order everything to search and destroy if I want only a small subset of my ships defending.