As the tittle suggest, I was at first trying to get the best maneuver to use, but after a quick read, I don't think any of them really qualify at all when you first get the feature.
Let's first see the relevant text to pick the maneuver
"In addition, when a creature uses your Commanding Presence to make an attack, it can simultaneously use one Sanguine Knot combat maneuver that you know."
For me that means, the ally can activate a maneuver, the action cost already covered by the reaction spent. I think he could only attack if the maneuver includes an attack, but maybe that can be read as he always get the attack and activate the maneuver for free.
Let's list all 7 of the degree 1 and 2 sanguine knot maneuvers possible when you get the feature at lvl 5:
-Back to back - could work and be a good candidate, but the ally don't get to attack (open to interpretation). It will only last until the start of THE ALLY'S next turn, so maybe it's over before the bonus to AC matters;
-Double tackle - expensive maneuver (3 points!) but would work. It expends another reaction from a 3rd ally (or the marshal) in order to work, making it even pricier.
- Doubleteam - a good cheap maneuver to choose, requires a bit of setup, and again, I'm not sure the ally gets to attack as well.
- Dual grapple - very specific and niche, you need a third ally already grappling or initiate the grapple yourself with the first attack and have the ally adjacent. Don't think it's a good option
- Legion stance - already been discussed in another thread, although I as a DM wouldn't allow for out of combat use, even though it seems to be RAW. If you are allowed and attack as well, could be good, see final note
- Shield wall - same timing problem as back to back, with the caveat you both need a shield. Not viable in my opinion, or at least very niche.
- Shoulder check - it's already a reaction with a very specific trigger, I don't think it can work at all with combat directives, but, as usual, I'm open to be proved wrong.
So, I don't know, it seems Legion Stance and Double team would be good. That is IF the ally gets to attack on top of the maneuver activation.
I think if the ally can't attack, none of these are worth you giving up your attack in the first place.
Thanks for reading the long post
Let's first see the relevant text to pick the maneuver
"In addition, when a creature uses your Commanding Presence to make an attack, it can simultaneously use one Sanguine Knot combat maneuver that you know."
For me that means, the ally can activate a maneuver, the action cost already covered by the reaction spent. I think he could only attack if the maneuver includes an attack, but maybe that can be read as he always get the attack and activate the maneuver for free.
Let's list all 7 of the degree 1 and 2 sanguine knot maneuvers possible when you get the feature at lvl 5:
-Back to back - could work and be a good candidate, but the ally don't get to attack (open to interpretation). It will only last until the start of THE ALLY'S next turn, so maybe it's over before the bonus to AC matters;
-Double tackle - expensive maneuver (3 points!) but would work. It expends another reaction from a 3rd ally (or the marshal) in order to work, making it even pricier.
- Doubleteam - a good cheap maneuver to choose, requires a bit of setup, and again, I'm not sure the ally gets to attack as well.
- Dual grapple - very specific and niche, you need a third ally already grappling or initiate the grapple yourself with the first attack and have the ally adjacent. Don't think it's a good option
- Legion stance - already been discussed in another thread, although I as a DM wouldn't allow for out of combat use, even though it seems to be RAW. If you are allowed and attack as well, could be good, see final note
- Shield wall - same timing problem as back to back, with the caveat you both need a shield. Not viable in my opinion, or at least very niche.
- Shoulder check - it's already a reaction with a very specific trigger, I don't think it can work at all with combat directives, but, as usual, I'm open to be proved wrong.
So, I don't know, it seems Legion Stance and Double team would be good. That is IF the ally gets to attack on top of the maneuver activation.
I think if the ally can't attack, none of these are worth you giving up your attack in the first place.
Thanks for reading the long post