There is one additional misconception on this that is more historical than legal. Many have referred to the need for Trump to use the same authority that Franklin Roosevelt wielded during World War Two. But the situation in this case is different. Back then, there was considerable control exercised over industry, though most companies had voluntarily agreed to retool to make the necessary equipment for obvious business reasons.
It was primarily through the control of raw materials and prices that the federal government could exercise chokepoint control. It could expand agricultural production, not by taking over farms, but by setting the crop prices high to encourage expansion. Even with massive national control, it took about 18 months for a coherent system of production to emerge, and that effort was largely based on price and resource controls.
Our leaders need to play to their strengths to fight the current war. The coronavirus battle must be won in months and not years. The only way to do this is to use existing structures and markets. Vastly different situations are presented in each state, some with relatively small numbers of cases while others like New York face a full fledged pandemic. Indeed, this is precisely where federalism is a strength rather than a weakness.