But let's say each company gets half the capital. Let's say that after a year one company has done better financially and distributed the profits among its workers. The other company invested the capital in a worse way and their workers are getting paid less. So in the next round, when more capital is again available (from whichever magic fountain the original capital came from), should both of them still get exactly 50% despite the fact that one company has better track record in investing capital and improving the wages of workers than the other?
You are simply stuck in a capitalist dog eat dog mentality.
There's nothing "dog eat dog" about the capitalist mentality. When you do better than the firm across the street and customers come to you instead of to them, you aren't deriving nutrition from the other firm, as though "its" former customers
belonged to it, like body parts. You and your new customers are simply living your lives without carrying the other firm as a burden.
In a worker run system the better companies share knowledge with the weaker companies in attempts to make them stronger.
It is not about total domination.
It is about trying to have as many good companies and therefore as many good jobs as possible.
That's make believe. In a worker-run system the better companies keep their trade secrets to themselves in order to retain their competitive advantages, keep the customers coming, and thereby pay themselves better than than the weaker companies can afford to pay. Likewise, they invest their profits not in having as many good jobs as possible, either by sharing with the weaker companies or by mass hiring, but in growing their business faster than their headcount: by increasing their capital/worker ratio, so they can supplement the market wage for their labor with the market return on investment. They act, in short, precisely like partnerships of little capitalists.
This behavior gravely disappoints the so-called "anarchists" who brought about the worker-run system. They went to all that effort and struggle and revolution or political agitation to reorganize the economy around the worker-run business concept, in the sincere hope and faith that it would end the capitalist so-called "dog eat dog" mentality and lead to as many good jobs as possible and an explosion of selfless sharing; and now they see nothing of the sort happens. At this point they have two choices. They can grow the first speck of critical thought and intellectual integrity in their lives and admit to themselves that their theory was wrong, or else they can find a scapegoat to blame the outcome on. Inevitably, they do the latter. And they do not have far to seek for a plausible scapegoat: it's all those selfish workers at the better companies.
So at this point, in order to strip those scapegoats of their ability to selfishly keep their trade secrets and profits and capital all for themselves, they redefine "worker control" to mean, not each company being run by the workers at that company, but instead, all companies being run by all workers collectively. Of course, having the workers in one company vote on all the policy decisions for that company is feasible as long as the company isn't too big; but having the workers at each company vote on all the completely different companies' policy decisions is utterly impractical. So instead of direct democracy, the so-called "anarchists" will resort to representative democracy -- workers will be told that in lieu of running their own company they instead may elect delegates to a central policy-making body, which will make the actual decisions about policy for each company and order each company's workers to share their knowledge and capital. Because the truth is, the self-styled "anarchists" actually care a hell of a lot more about sharing and equality and having as many good jobs as possible than they care about anarchism.
So the end game for a "worker-run system" is that workers are still taking orders, still having their wages and working conditions set by somebody else, still told who's hired and fired, and still having a cut of what they produce handed over to people who didn't do any of the work. So what's the substantive difference between that and capitalism? Mainly this: in capitalism, there are thousands of different committees giving orders and receiving a cut of production; in the "worker-run system" end game, there's only one committee. Nice work, "anarchists". You've shut down the market where in order to get workers, buyers have to compete with one other by offering better wages and working conditions than the outfit across the street, and you've made everybody move into your newly created "company town" where there's only one buyer, so workers have no choice but to sell their labor to that one buyer on whatever terms it decides.