Alex, if it's okay, I'd like to suggest what is said in those notes, that is, leave the choice to the player and include this as an optional order.
Admittedly the Rampart fleet is an extreme example since these are slow ships that move about mainly with a burn drive, so burning in the wrong direction can be fatal; but that just makes it more pointed, the issue is still there eg. your Conquest fleet losing because 2 of the Conquests go chasing a Lumen; Radiant spinning around trying to catch a Lumen with its frontal guns, etc.
It would be great to have it as an optional order for when the player feels it is right, for example then you could give it on slow ships that are not meant to chase frigates while still having your frigates chase frigates. While ignoring frigates can be bad, missing a slow capital from the line of battle because it is distracted is not just disastrous (turns clean victory into potential straight up loss or Pyrrhic slog of death waiting for it to come back while taking losses. What is worse, it is a loss that feels very unfair and frustrating to the player.
If it were an optional order that existed, the responsibility if a dangerous frigate is ignored rests on the player. You could title the order "Hold the Line' or something.