It seems to me like all of the couples that were in it came from random fanfictions. You know what I mean...
And thus, Finn becomes part of the shipping industry. Though, he was more of an experimental shipper. The reason it goes from playing with these little people to pairing them is from what Jake said at the beginning, when he was talking about romances and such.
What could these little people's purposes be used for? As in, the point of Magic Man leaving them to Finn secretly? I don't even think he knew a bunch of them. He probably wanted to make his own version of the Sims.
As for the dolls, they seem to be in their own universe, yet speak like Charlie Brown adults. To me, it seemed a bit more interseting than Farmworld. They also seem to have intelligence of what their character does (like mini-Jake playing viola). Other than that, they just kiss each other and cheat on people.
Another thing, when miniature Finn and miniature Flame Princess kissed, it didn't make an explosion or whatever.
If anyone else noticed, Abracadaniel and Zergiok were in the main list, but Marceline was in the c-list. What the flip, Finn.
BUT. What if in the miniature dimension, a mini-Magic Man gave mini-Finn that same sack, then that Finn played with the toys inside it, where he found a mini-mini-Finn, then that littler Finn got a sack from an even smaller Magic Man, and so on, making a continuous paradox that never ended?
It seems BMO x Ice King could be a possible ship.
Finn and Magic Man: "I'm not coming back!"
R.I.P Little Peppermint Butler