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I like how Infantry Company, by mid- late game (I play 3 v 3) benefits immensely from Supply yard 1 and then 2. The units from off-map combat group are not always what you need but they come at a massive bargain (the cost savings are sometimes up to 140 fuel and 350 MP or more) and there's usually a way to use them. The lack of delay means that you can deploy them immediately without waiting for some sort of buildup which is an advantage.
Actually it could be much more. You get at least 1 rifle squad (270), 2 AT (maybe 1 of them is an m8) which can bu 560-600, and an mg/mortar/ranger/rifle. Total you can have 1070 to 1270 mp worth for the cost of 800. But you might get 3 units instead of 4 where you are sure to get shortchanged. But I have never had this happen to me though I have seen it in casts. I don't know how that mechanic works.
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My favorite part of Airborne doctrine are the fuel/muni/HMG/mortar packages and the AT guns. Everything else I find a bit prohibitively expensive (air recon is too short, strafing run is too expensive, airborne is too expensive) although the bombing run is great if it connects (250 munitions).
Learn the best use of strafe. The mechanic is that the more target elements there are in the area the more damage is done to each unit. If you strafe 1 sniper in a field it will suppress and reveal it, but it will do little damage. If you strafe a blob, particularly if the blob is near other target elements (a building has many, including windows, etc.) and/or tightly packed, you will get squad wipes, possibly multiple squad wipes.
This has lead some to refer to the "HQ strafe exploit" where you strafe the HQ area right after a big retreat. The HQ is a big building with lots of target elements and with the models all clumped in one area. If other Axis buildings are near you can add their target elements too.
That makes the strafe very powerful for a 150 munition strike that gives no warning.
More info on using it well: It has a wider area of effect that the targeting rectangle and it will take longer to hit on larger maps (the plane has to start on one edge and fly towards the target area... the bigger the map, the longer the flight.)