One other question. Does anyone know good ways to encourage countries to trade for your resources? I find as the Netherlands I'm chronically short of steel, but have lots of excess aluminum and oil that other countries don't seem to be that interested in.
Defenders get fortification, or entrenchment or something like that, I can't remember what it's called of the top of my head. The main ways to boost that is to have engineer companies and have the current engineer tech and the battleplan doctrine, which gives pretty big bonuses to both planning and fortification.
I'm reluctant to choose my doctrine based solely on this since I actually intend to use the Continue the War in Batavia focus to take control of the colonies and fight on from there. I'm mainly just trying to put up a good fight so I can get some legitimacy for my government in exile and make things costly for the Germans.
I've actually tended to go with Superior Firepower as my doctrine as it fits thematically. The Netherlands don't have a lot of manpower, and the division template I plan to use is rather heavy on artillery, AA, and anti tank guns.
I admit I don't think I have ever used the training function for any of my airforces, I suspect the boni might be nice but since I am always short on aircraft it just never seemed worth the attrition you get from it.
You get an entrenchment bonus simply by not moving which you can increase by techs and adding engineers for example. If you can force the enemy to eat a river crossing penalty its even better and forts can be useful though only if you have a relatively short frontline (for example you can make the border crossing germany and france into a bulwark the AI is never going to break) since the opportunity cost of placing them can be quite high. If you are up against tanks it might also be worth throwing in the anti tank company to prevent them from accomplishing breakthroughs. Terrain wise mountains are also perfect for defence but you are the netherlands so not exactly something you can make use of.
Also since you speak of strongpoints, you will always need to defend the whole line since you can have as many boni as you want if you get encircled you die...
As noted above, I'm not short of aluminum or oil as the Netherlands, so I can build a pretty big air fleet.
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I had my air forces running constant training in order to ratchet up experience points so I could upgrade my fighter models (though I do tend to restrict them to daytime training to reduce the accident rate).
Since I'm planning to Continue the War in Batavia, past a certain point building factories is basically giving them to the Germans for little gain. So I usually switch to fort construction towards the end of the lead up to war.
I've generally included an anti-tank division in my the divisions I plan to use to hold the fortifications. I've actually been thinking of including more then just a company actually. I've already got multiple battalions of artillery and AA. (I actually feel like my divisions are kind of ridiculously ahistorical with the number of artillery and AA batallions they contain, but then its not like the Netherlands went into war with the Germans with over nine hundred fighters and two hundred naval bombers either.)
Anyway it sounds like I'm mostly on the right track, though maybe I should try harder to get my Engineer companies upgraded to Level II (I've tended to upgrade my Recon companies to II first).