I'm not very far into the game, still in fall 1936, but I'm having severe issues generating enough WSU to cover the needs of the Nationalist army. I've yet to build any units beyond the options deploying African forces, and I don't imagine myself doing so anytime soon given the WSU constraint. I can't spare the WSU to create sufficient replacements for the artillery I start with and periodically gain as part of the African armies, let alone the massive WSU investment that getting the Italian armor I received recently into fighting shape would be. I imagine that any further armor I receive from the Italians or Germans will be useful only for as long as I can maintain their initial strength.
My fundamental concern is less that the Nationalists begin with resource issues and more that that this problem won't go away. Looking at the resource distribution on the map with the supply filter, WSU seems to be relatively rare compared to manpower or money, and (thus far) I lack the ability to requisition it through regional decisions in the same way I can for manpower or money. The Nationalists also seem to lack the options to create WSU producing factories that the Republicans possess. Given my current situation, the only scenario in which I can imagine that I will have enough WSU to cover my needs (being solely replacements and not unit construction) is one in which I control a large majority of Spain, at which point the game would likely soon be over.
Any solutions, theories, thoughts, etc. are more than welcome.