What about cloaked cheap AT gun in T0?
In Order to counter the m3 the Raketen needs to be build as 3rd unit. And even then it's kinda easy to circle the Raketen with m3 because of its slow Setup+aim+hitting the ground.
You already have a hard time contesting map presence because of penals and mg (maxims and or dshka ), Adding a Raketen early in your build doenst really make that better.