I haven't had time to dig into the math of how many ventilators are likely to be needed using the models you cited, and the previous modeling by CDC and the various state health departments.
I suspect President Trump with his natural political skills realizes that trying to explain to the public how allocation would really work is not likely to work, particularly given hostile governors and the press. A simpler solution is just flood the requesting states with more ventilators than they can possibly need, along with enough masks, gloves, etc. to bury Manhattan in them. (Of course innovative nurses and doctors are already inventing ways to safely conserve PPE).
Then, nobody can complain that President Trump didn't provide the equipment they needed. Since other countries will want them too, we can just sell or donate the extras or put them in storage for the future. Plus it gets some manufacturers back to work.
Trump is ordering the ventilators also to sell them to other countries such as the UK!!