these 'money first' people don't seem to grasp that our current monetary system is largely an effect, not the cause, of the underlying exploitative social relations of capitalism
you could have all the money in the world, but if you can't go out and buy labour with that money, it's not going to make you a capitalist, no matter how much you have of it. In other words, capital as we know it would not exist. If wage-labour doesn't exist, surplus value doesn't exist, if surplus value doesn't exist, capital doesn't exist. this is the fundamental ability of capital to exist, to grow, to valorise itself.
this 'money first' approach is similar to the idea that you could negate/abolish the catholic church by formally getting rid of the pope but changing nothing else - it mixes up essence & appearance, substance & form
Marx (sorry BB) actually makes the point somewhere in Volume 2, that although money is an obvious requirement for value to circulate and pass its way through the circuits of capital, that the most ideal situation from a point of view of the production of value (i.e. exploitation of labour) is the case where a capitalists's commodity product is sold not for money, but for the productive capital inputs that are required to re-start the production process. As this minimises the amount of time value spends in the sphere circulation (i.e. the money capital and commodity capital forms) and maximises the amount of time value spends in the productive sphere (i.e. in the production of value, through exploitation of labour)
fairly straightforward logic really in that although capital clearly needs to fully traverse the circuit from money to productive capital to commodity capital and then back to money again, value itself is only produced within the production stage, so the ideal situation is for the time that value is spent in the money and commodity form's should be minimised, hence efficiencies in transport/communication/circulation etc.. are key to an efficient traverse of the circuit and to allow value to 'work harder' and spend less time in the forms that does not allow it to directly valorise itself
So taken to logical conclusion an ideal type capitalism (from a maximisation of exploitation perspective) would skip the stages of commodity capital being turned into money and that money then being turned back into productive capital and instead the commodities coming out of the production phase would be converted immediately back into the productive capital inputs of means of production and labour - he wasn't suggesting that this would ever be possible practically but from an ideal perspective this would be the most efficient (if an efficient way of doing it could ever be found).