A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 18 May 2013
I've got a question about a scenario where you have 2-3 copies of hida defenders at the battlefield. If your personality with one attached uses an action that moved, destroyed or bowed an enemy personality at the battlefield, can you react with the other copy/copies to gain more than 2 honor? Or would you need to have the other performers with the defenders attached use an action to react with them.
Example A: Utaku Lishan x3 oppose an enemy personality at a province and all 3 have hida defenders attached. Lishan A plays Surety of Purpose to bow an enemy personality who ends up being bowed. Would all 3 defenders react and gain 6 honor for the player or would only the defender with Lishan A react and give out 2 honor?
A player, 18 May 2013
Hida Defenders read: Reaction: After the resolution of your action that bowed, destroyed, or moved a Personality who has opposed this card at the current battlefield: Gain 2 Honor.
Note that nowhere in the action does it require the action to be performed by anyone in particular. The requirements for reacting with Hida Defenders are a) that the Defenders were at some point at the current battlefield (not necessarily now), and b) they were opposing a Personality, and c) your action bows, moves or destroys that Personality. It is irrelevant whom are they attached to, or who does perform your action, if any. So yes, you can react with all of them if they fulfil the three conditions I listed above.