I agree with youThere's multiple universes where
How does that help them die? They're supposed to die in the battle. (See also The City on The Edge of Forever) That's why the timeline is all screwed up. The didn't die there. The reason to accept their sacrificial return is for the cause of ensuring respect from the Klingon Empire. That's the catalyst for an eventual peace treaty with them. Klingons respect dying in battle even more than victory.
Being victoriously rescued by Starfleet from a Romulan attack might not necessarily engender the same respect as dying, during the effort to, as they had originally done
But sending someone to guaranteed death is difficult.
