We aren't really all that far apart I just realized.
DND, if most people do freebies with very few mutual trades you have a version of the Piggy Swap.
And the Piggy Swap had 1:1 trades although we didn't think of them as such. Someone would ask me for something on my list & I would say yes & then immediately ask them for something on their list.
So really it is all in what rules you set up to ensure that the majority of people come out of the swap feeling like they got a good deal!