You need 1 Stuka to decrew and decrewing vetteg B-4 is equal to losing it.
Off map frim Jadg doctrine can wreck B-4 if it's builded near point.
You can use also Falsch or Jaeger on many maps to decrew it.
All you need to do as Axis is to veto some maps like crossing woods where B-4 is base can rape Axis base.
But on the other hand Train and Steel (I belive it's name in english) is a map that allows you to use falsch very efficiently and B-4 has to be build outside of the base - at least first line of points.
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B-4 buff is not needed.
If i spend 240 MU on recon + stuka i expect it to be destoyed.
I am cutting 4 LMG/Shreck/almost 5 tellers Mines to do that.
Also if hes dumb enough to build a b4 next to a strat point its a l2p issue.
For referance the english term is "Rails and Metal"