Zero sympathy for the employers here, as it's either a) a sign all the work is being done at a price the company is willing to pay, and these people are just fine where they are, or b) it's a sign the company is poorly managed, which is obviously the fault of the managers.

Realistically, I think it's completely fine to have less-than-fully-worked employees available to cover issues as they crop up, work through projects when the extra effort is needed but otherwise just generally stay ready to go and in a relaxed/healthy state.

I wouldn't call these folks the highest achievers, but if they're okay with that, and it seems they are (at least temporarily), doesn't seem to be a problem to me.

IMO it's so much better than constantly hiring/firing to try and find that "exactly right" employee count.