I saw a cap of two divisions - he couldn't send more.
It was a complex situation, however, in game terms the deploying of volunteers to an civil war is the more accurate model since the fighting was restricted to the Korea peninsula. In the game, if one country was at war with another, it would be a general war.
Yes I went back and looked at it and there was a cap of 2, based on the number of divisions Germany had at that time, so if the SCW broke out in 1938 when Germany had 4 times as many divisions they could have sent 8? I also read the DD and it said democracies can't send volunteers, meaning the Republicans can't get the international volunteer brigades, who outnumbered the Germans.
I think the following types of aid should be possible:
volunteers who are added to the manpower pool so that new units can be formed - no impact on broader international relations/world tension and the sending country gains land experience based on number sent. There should be limitations based on world tension and government type so that dictatorships can send more.
equipment added to pools so that new units can be formed - small impact on international relations/world tension. Combined with the info from the DD about lend lease, the equipment sent would earn experience points as it was used. Again quantities would be limited by government type and world tension.
formed units - bigger impact on international relations/world tension that rises as commitment rises
Under this sort of system many European/Western countries would send some volunteers to Spain to get land experience and arms would flow, primarily from non-democracies. The Germans however may be reluctant to send actual divisions due to the impact on world tension and Germany not yet being ready for war. However Italy sending a few divisions may not raise tension that much as it was already somewhat of a pariah due to its conquest of Ethiopia. As more nations send arms and divisions to a civil war, world tension increases allowing more to come from more nations and there is the potential that a civil war could explode into a war between nations if participants are not careful.