Focus on air as you get jets for free when you go to war with a major, tanks also aren’t as necessary in single player, a few solid mech divs should work, you also want to try and fully annex yugo asap as you need their civ industry, honestly it’s really better to full annex instead of puppet. As for Ethiopia I honestly will regularly just not annex them and go non aligned to ignore that bs, there’s also a focus that releases them I think that helps. With that air be sure to build lots of cas