I believe the cost of training replacement workers + the cost of paying replacement workers' salary + the cost of paying for enhanced security would still be significantly cheaper than paying UAW workers approximately $75 an hour in pay and benefits.
Charles Grassley and a couple of other Congress-critters used to do that with USPS to show that USPS gross productivity was crap, and getting worse. Then, one day, it got better ~ Chuckey Jr. there shut up about it. Dick Strasser, who is retiring this month, didn't.
Guess it depends on who you want to impress, and with what.
Whether they actually produce something or not...