To expand on this (and hopefully not mangle your original idea), the key feature that makes a capitalist economy efficient is the use of a price mechanism to distribute the hard problems of decision-making to people who are reasonably well-informed and well-incentivized to make good decisions. These decisions will benefit society as a whole when (A) property rights exist and are enforced, (B) there are low barriers to entry, (C) transaction costs are low.

(There will be failures otherwise. Pollution ends up under A, monopolies under B, and a whole host of modern stupidities ends up under C — e.g. just for instance, no one at a minimum wage job is going to afford a lawyer to negotiate their employment contract: transaction costs are too high; the bigcorp employer, by contrast, only has to draw up the contract once. Instant structural unfairness follows.)

Orchestrating both information and incentives like this is really really hard. It's hard enough at a mid-sized project at a mid-sized company, where management spends hours and hours hammering on the idea of "alignment". At the scale of the global economy it's utterly intractable.

it appears that yout descruption equally applies to ancient rome - property rights were neforced, including on people. Price mechanism was used.

Was ancient Rome capitalist?

Ancient Rome, famed for its commerce, had a variety of capitalist features, though with significantly less productive use of invested capital, as one would expect of a pre-industrial society. Most people, however, would consider Roman slavery with people-as-property to be an abrogation of property-rights-in-the-self rather than just enforcement.

You could say the same thing about every other economist at the time or even much more recent ones. Things change and evolve.

Marx identifies 5 functions of money in the 3rd chapter of Capital Vol 1 called "Money," not to mention the expanded treatment of money by Capital Vol 3.

https://www.marxists.org/archive/marx/works/1867-c1/ch03.htm

It's unclear what you think Marx said on "how" to end capitalism and how this relates directly to his theory of money.