Orders, especially Formations and escort orders are nice tools to influence the behaviour of the fleet.
I tend to use them on most of the ships, but am a bit put of how much work it is to establish the links.
Here are two ideas how to speed up the process:
Connecting two ships could be done by one mouse drag, without using the orders at all. Formation modus could be activated by by CTRL-Key or as an extra tool button or when hovering over a special connection point at the ships silhouette… Just think Vector Graphics program.
Attack priorities highly depend on ship-design. Why not allow a standard behaviour to be defined already when the ship is designed?
You could still change it for individual ships in the fleet, but it would not be needed for each and every ship.