Well, first of all, the strategy is unlikely to be Trump's, which should be unsurprising, because it's actually good strategy; it just reeks of desperation.
See, when your resources are limited, you don't spend them on the close states if winning only those close states mean you still lose the overall election. Trump is at that desperation moment where he has to hope that all the close states fall his way, and move his attention to states that are a bit further from close, hoping to push them close enough that they might similarly fall his way.
If you assume that the polls are off in this election by the same margin as in 2016, the states that are most worth pushing in are PA, MN, and AZ, while hoping that the rest comes out his way.
This is just a hail mary.