So Kirk was brought back to deal with V'Ger and took over for Decker. He convinces Starfleet his experience is essential. Uhura says (in the extended cuts) that their chances of returning in one piece doubled because of Kirk.
But did having Kirk in command really make a difference?
It seems to me that what made the difference was Spock. Spock helped Scotty fix the warp engines so they could get to V'Ger in time. Spock figured out how V'Ger was trying to communicate so that it stopped its attack and let them come inside. Spock mind melded with V'Ger and figured out what it was missing/needing.
But suppose Decker had been in command and only Spock, not Kirk, had joined. Would anything have played out differently? Decker would have delayed entering warp until the engine imbalance was created, which would have been the right call and avoided the wormhole. Decker might have been quicker to run scans and raise shields, but I don't think that would have changed anything because ultimately even with Kirk's more reserved approach, V'Ger attacked them any way.
Do we see anything at all that actually indicates Kirk being in command helped the mission?
But did having Kirk in command really make a difference?
It seems to me that what made the difference was Spock. Spock helped Scotty fix the warp engines so they could get to V'Ger in time. Spock figured out how V'Ger was trying to communicate so that it stopped its attack and let them come inside. Spock mind melded with V'Ger and figured out what it was missing/needing.
But suppose Decker had been in command and only Spock, not Kirk, had joined. Would anything have played out differently? Decker would have delayed entering warp until the engine imbalance was created, which would have been the right call and avoided the wormhole. Decker might have been quicker to run scans and raise shields, but I don't think that would have changed anything because ultimately even with Kirk's more reserved approach, V'Ger attacked them any way.
Do we see anything at all that actually indicates Kirk being in command helped the mission?

