Yes, Vincent's stay was shortlived. He was captain of the tour to South Africa and thats about it
That's wrong. You must have misread something you googled.
Vincent was the All Black captain in for the first two tests against the Boks in the epochal 1956 tour of NZ. He and five-eight Bremner were the halfback and 1st five of the dominant Canterbury side of the day, long before the days of the NPC. They had held the Ranfurly Shield for about 3 years and the pair were supposed to be the best pairing in the country.
The Blacks lost the 2nd test and several players were dropped including Vincent and Bremner. Two of the players that were brought in were the legendary fullback Don Clarke, a young giant who was bigger than some of the forwards - and another legend: prop Kevin Skinner, who in front of my young eyes at Lancaster Park, sorted out both Bok props Koch and Bekker, after switching sides of the scrum, because they were cheating, in his opinion.
But I could write a book about that tour - and no, I didn't have to look anything up that I have just written.