Ok - it's very late where I am and I don't have the energy to eloquently justify this (or think it through), so please bear with me.
Attack command is used mostly for the enemy-relative command, not for the "orbiting" UI or anything else. So players have one UI for grid-relative movement (move, strafe, etc.), and another UI for enemy/ally-relative movement. IMO that's just overcomplicating things, and can actually have a pretty big impact on how fights happen.
This is not a fully fleshed-out idea, but what if players could set a relative movement target (grid, x ship, y part) and still issue normal movement commands? So you wouldn't need to "attack command" an enemy ship to hold position relative to them. You would just say "commands are now relative to that enemy" and issue normal movement, strafe, etc. orders. Would probably need 2 commands, one for grid-relative angle and one for ship-relative angle.
Tldr: unify the grid-relative command UI and the ship-relative command UI