I really, really hate to do this, but I really, really hate inconsistency more, so I have to.
Grit. (You are not prevented from moving while you are engaged by only 1 squadron.)
Heavy . (You do not prevent engaged squadrons from attacking ships or moving.)
If my squadron is at range 1 from an enemy squadron, and an enemy squadron with HEAVY, can it move away? I have to say yes, I can move away, since HEAVY does not prevent engaged squadrons from moving.