There is a problem that comes with operating at scale: yes, there are economies of scale, but they only work to your advantage when everything is running smoothly. When things are not running smoothly and you are for instance losing on every product sold those losses mount extremely rapidly. Car manufacturing is a scary undertaking for exactly that reason, especially in the Model 3 segment (where a certain amount of luxury is expected and fit and finish matter but the budget is much lower than for a luxury vehicle). There is not enough margin for error to fuck up your production, it will eat all the profits and then some.
That is why the problem of having 200 roadsters in a warehouse pales in comparison with the problem of having an assembly line that is supposed to crank out 5000 vehicles crank out 2500 (if that) instead. It means that you are losing money hand over fist, your capital expenditures and wages are identical but your income (if properly recognized) is half. This will totally wipe out your margins for quite a while to come. Car manufacturers have consolidated for a reason, even a small hickup can kill an otherwise healthy company.