One thing I really like about the new Combine has to do with co-ops, especially the new co-ops for crafting cottage recipes.
The way co-ops work is that once you join the co-op the system keeps track of how many plots of a specific crop that you seed. Only that many plots of that crop count toward the number of plots harvested for that crop for that co-op. However, they do not keep track of which plots are which. They just keep a count.
So how the Combine helps here is as follows.
Unless you have a billion neighbors, all with the same kind of crafting cottage, you're going to end up doing that co-op a few times at least. Let's say you are the one who Completes the co-op (the first time). You're also going to start the second round of the co-op. However, ou've already got some more of your farm planted, and of course all of your neighbors who were in on the co-op probably have their farms planted as well. This has always been an issue with co-ops... how to make these plots count for the second round of the co-op?
What some people have done in the past is harvest a plot, plow it, seed it with the same crop (and so now the count of plots seeded is +1). Then, when you do the same to the next plot, the harvest of that plot counts toward the second co-op (because of the +1). Using this leap-frog approach, you can basically avoid the "wasted harvests" that typically happen in-between co-ops. However, harvesting, plowing, seeding, bit by bit, is tedious.
The Combine does that work for you. The first set of plots are indeed "wasted", but since you're harvesting, plowing and seeding in that one click, the plots you point the Combine at for your second click count toward the second co-op (because of the seeding you did with your first click!) So only that first set of plots are "wasted"... all the rest of the plots you process with your Combine count immediately toward the co-op, for both seeding and harvesting.