You don't have to. If it becomes capital, then it is subject to the same multi-stakeholder analysis.
If I bought a printer, it would just be a commodity. If I start selling products made from said printer and hire more people, then it would need to be a worker coöp.
How would an authoritarian socialist system handle someone wanting a printer given that it could be used as capital?
As a Mutualist, I firmly disagree. Coöps are essentially a democratic alternative to top-down coercive management styles or forms of ownership. It is a mutualist system that is antithetical to competition.
Take a renter's coöp for example. Essentially everyone owns their building and they aren't competing with other buildings or have shareholders would expect a return on investment.
With coöps you can actually respect locality. Large auth-socialist systems will often have with people competing interests who have undo control over local systems. That isn't to say broader standards shouldn't exist, but that they should be done thru voluntary industry wide syndication.