Wait a minute.... that article says that the contents of their stomachs can be up to a third of their weight. Add 3/4 of their weight is poop, and that's more than 100% of each sloth being either digesting leaves or digested leaves.
I think that it probably goes like: 0/0, 30/0, 0/25, 30/25, 0/50, 30/50, 0/75, so that one in emptying into the other fast enough to avoid overslothing, assuming 5% goes to making the sloth fatter. This allows for a minimum "neither tummy nor turd" 20% sloth floor value.
If that were increased, we would instead see a series with smaller and smaller non-zero values for fullness as we approach maximum sloth fecalness.
