There are a couple of problems here from a marxist perspective. First if the profits all go to the workers and they use it on consumer goods how can the economy expand? In that scenario there is no surplus product left the entire societal product is consumed. Second problem: Are the coops competing with each other on a market? Then the coop which pays itself the lowest wages has a competitive edge and can expand it's market share. The other coops would have to reduce their wages as well to regain competitivness and in the end the wages would be the same as before. If we assume the coops are not competing with each other how is efficiency maintained? In capitalism the efficiency of a company is identical with it's proft rate since profit is all capitalism cares about, but profit rates are only somewhat sensible if the companies compete with each other. Otherwise there is what? An agreed upon proftrate? That breaks all correlation between productivity and profit so noone would notice the loss in efficiency until the shelves are empty.

Now if that society had an economy of time, efficiency could easily be measured and maintained as you just calculate the time of work that goes into a product and then if you need less time after changing something it is objectivly more efficient. That I believe is the actual marxist position, but since the post shows "pounds" as measuements and not "hours" I assume that is not what is meant.

I think we should be highly critical of MMT or "market socialism" scemes that try to fix capitalism. If only we printed more money... if only it wasn't for the yachtowners... No! Capitalism is inherently contradictorily. The point of Marx never was nor could ever be to fix it, the point is to end it.