Saluting?

[Magnus]

You're going to have to abandon most of your pre-existing military ways of thinking when it comes to the Roman Army. Just because it makes sense to us, doesn't mean it did so for them. And using modern examples of military doctrine as a comparison to the Roman army more often than not doesn't work.

The only "evidence" as you suggest of saluting is hand gestures which we assume to be some kind of salute. That's a large assumption considering we don't know the context of those gestures.

Another aspect that is going to back your noodle is that there is ZERO evidence for the romans using a specific foot to call drill movements on, and also no evidence for an executive and precautionary part of a drill command. Yet many reenactment groups do it, because they can't get their heads around it.