Two teams of two players (strong + weak vs. medium + medium) is fairly common, I think. It’s called ren go. But 2 vs. 1 would be different—the team of 2 players would be handicapped not just by the weaker player, but also by the lack of communication. This is a possible way to handicap, sure, but it can’t be tuned as precisely as komi or even star-point handicap stones. Precision is an important consideration for handicapping.
I’ve also seen another method where two players of unequal strength played an even game, but a stronger third player teamed up with the weakest player. They didn’t communicate, and didn’t alternate turns within their team—instead, the strong player was allotted a certain number of stones at the beginning of the game. Then when he spotted an especially big mistake by the weaker player, he could spend a stone to correct that move. This might be categorized like asymmetric time controls: the weaker player gets more resources.
Two teams of two players (strong + weak vs. medium + medium) is fairly common, I think. It’s called ren go. But 2 vs. 1 would be different—the team of 2 players would be handicapped not just by the weaker player, but also by the lack of communication. This is a possible way to handicap, sure, but it can’t be tuned as precisely as komi or even star-point handicap stones. Precision is an important consideration for handicapping.
I’ve also seen another method where two players of unequal strength played an even game, but a stronger third player teamed up with the weakest player. They didn’t communicate, and didn’t alternate turns within their team—instead, the strong player was allotted a certain number of stones at the beginning of the game. Then when he spotted an especially big mistake by the weaker player, he could spend a stone to correct that move. This might be categorized like asymmetric time controls: the weaker player gets more resources.