I don't think splitting wins should happen at all. Though the idea is interesting, it just doesn't make sense for SG. This isn't the Hunger Games where your life depends on it, it takes multiple weeks to do one round, and there are thousands of crazy lunatics that will get extremely emotional over what happens.
The games are less than 15 minutes each (unless it's SG Classic, which you're probably playing because it's longer). You can always just do another round afterwards if you want. If you can't play multiple games to get each of you a win, why are you playing in the first place? I don't see any point in playing just 1 game, seems too much of a hassle to do everything.
Overall, I like the idea, but I don't want it implemented because it just makes no sense for the Minecraft Survival Games.