I assume this is the case at all levels, but at level 3, the Cutter states that it takes 4 buildings to saturate a belt. This is confusing since they have 2 output belts. If you build 4 cutters, you will have 2 fully saturated output belts. The case where this came up and was confusing for me was the Rotated Stacking task. I was using a RbRuRbRu as a base and cutting it in half to use both pieces for stacking. I was confused why my inputs were backed up when I connected all 8 outputs of the 4 cutters. I then realized that if you're combining the outputs, you only need 2 cutters. So for one belt of input, I have it going into 4 cutters, 2 output to 1 belt, the other 2 output to another belt.
I'm not sure if this is a "bug" per-se, but it is definitely very confusing and should be explained better.