I’m a little surprised that some of the aspects of the Spanish Civil War that effected early war stuff hasn’t been mentioned (at all that I can remember) in any of the WW2 episodes. Prime example is how French aircraft engine production was still being slowed down because the HS engines were relying on foundry castings from the Spanish factories division of the French company! SCW will need several episodes in Between 2 Wars at least I think, especially to get into things like the Lincoln brigade & French / British / German naval neutrality patrols & such.
From the Italian side, the Ethiopian war in 1935 and later the support to Franco in the Spanish Civil war constituted a huge military and financial effort which slowed down RD of new equipment (above all aircrafts). In many accounts it is mentioned that a complete refit and modernization of the italian armed forces would have been accomplished by 1943, thus making Italy a country not able to fight a modern and total war in 1940.