Carrier Pigeon

Card Type: Strategy
Gold Cost: 0
Card Text: Absent Battle: If you are the Defender, target your performing Personality at any location that has not been at the current battlefield at any time during this attack and was not prevented from assigning to it this phase by card effects. Straighten his unit. Move him to the current battlefield.
Focus Value: 1
Legality: Age of Enlightenment (Lotus), Clan Wars (Imperial), Rain of Blood (Diamond)
Deck: Fate

Printings

Erratum: Reads, "Carrier Pigeon 0G 1FV Battle: If you are the Defender: Target a unit you control that has not been at the current battlefield at any time during this attack and was not prevented from assigning to it this attack by card or Stronghold effects. Straighten the unit. Move it to the current battlefield." [MRP, Lotus Edition, 31 October 2005] Rules Archive, August 18, 2007, p. 9
Erratum: Carrier Pigeon: May target a unit that was prohibited from assigning only by rulebook restrictions, such as because its Personality was bowed. [MRP] Legend of the Five Rings FAQ, April 26, 2004, p. 17
Erratum: Carrier Pigeon may still be played on a unit that could not have assigned if the only reason it could not assign is that it was bowed. [errata] Legend of the Five Rings FAQ, October 2003, p. 14

Q: 2) Wasn't it ruled a failure to meet the Rule of Relevance to use any action that would move someone who cannot attack/defend into the appropriate army, such as Matsu Domotai? I runderstand that this ruling was made specificly on Tireless Assault (though Carrier Pigeon and a few other cards could also come-to-mind), but why wouldn't it logicly carry over to other, similar, instances - regardless of the source?
A: It doesn't carry over "regardless of the source" because an action is Relevant if it's on a card in the current battle even if it doesn't target or affect anything there. Jeff Alexander, "rules for 17 Feb. 2004", 19 Feb 2004