How do you produce wool at a Nimbus Bed?

The pairing matters more than the count. A Nimbi in a Nimbus Bed is not just a working assignment, it is the best one available: nothing you slot in there will out-produce it. So when you are deciding where your Nimbi should go, the Nimbus Bed is the answer, and when you are deciding what to put in a Nimbus Bed, a Nimbi is the answer. The two questions collapse into each other.

That makes wool one of the easier resources to plan around. You do not need to test combinations or work out which member of the Nimbi family is the right one. Family is what the bed reads. Any Aniimo from the Nimbi family in that slot puts the bed at full wool output.

The practical consequence is that a Nimbi is worth keeping off other duties. If you have one assigned somewhere else and a Nimbus Bed sitting idle, you are leaving wool on the table for no gain.

Not settled: What a non-Nimbi Aniimo does in a Nimbus Bed is not settled. A Nimbi is known to be the ceiling for wool output; whether anything else in that slot produces reduced wool or none at all is a separate matter.