They have a few options of what to do while treating workers fairly, even under the framework of capitalism

• raise wages until workers are willing to work the nightshift permanently
• raise prices till demand matches the output you are able to achieve while treating your workers fairly
• increase production throughput by opening additional lines so supply you output matches demand
• bring democracy into the workplace and let the workers decide if they want to work rotating shifts so the company can save money

Fucking over your workers isn’t an acceptable option. As a society, we can’t accept people’s lives being made worse in the name of saving money.