I believe dominance should be determined by how independent the employees are - having transferable skills, not being dependent on a single job, being able to ask for increased job compensation without fear of being laid off, and if they are laid off, being able to find another job or resort to starting a business themselves - and that it should NOT be determined by how much power and force the employee can exhert over the employer, either through threats of union strikes, or legal controls and regulations.
I feel completely comfortable with my employees working on side projects, learning new things, and ask them to update their resumes at least once a year with whatever new skills and tasks they have picked up recently. I WANT them to feel like they don't depend on me, because them not feeling tied to me and their job actually keeps us on friendlier, more open, and more even terms, and keeps the business more productive and innovative. If my employees were in a union, or had some sort of control over keeping their job against my will, the work environment would have been a lot more stressful, with "me vs you" tensions rising often.