An arti is a big investment... be more aggressive and dont allow your opp to get it.
Dont forget to select the right commanders... if you are playing OKW + Ostheer the Ostheer player should have at least on counter to potential ML20s
(Stuka dive probably one of the best counter + recon overflight)
If you are dealing with light arti (USF Howitzer, mortars) try to use the german mortars (counter barrage can be very effective) or go for Spearhead doctrine (that one with the mortar halftracks)... but keep in mind it will be less effective against ML20s
OKW is very vulnerable to arti so the Ostheer player needs to focus on the counterparts
Stuka also not a bad choice
leave the ML20 uncountered is probably the worst thing you can do (the OKW player will lose all his buildings really quick -> Game over)
Dont camp... if you have secured 2VPs harass the thrid one or the cut-off/ fuel/ammunitions points.
