If a person can do the job that's expected of them I don't find it unethical (assuming they're not working for competitors, utilizing resources of one employer

If a person can do the job that's expected of them I don't find it unethical (assuming they're not working for competitors, utilizing resources of one employer for the other, etc.) They're not hourly employees and double-billing. Employers are dishonest and unethical all the time. Just because the norm is having one employer (to the primary benefit of the employer) does not make it unethical to have 2 jobs. Having said that, I wouldn't want to deal with the stress of one employer finding out about the other(s).