Its too cheap.
Should cost 10 Muni atleast.
Doesnt sound like much of a difference, but it will help prevent spamming as the Muni will start to add up, but also increases buildtime meaning it cant be so near instantly built and gives Ost a bit more of a chance to spot them being placed.
In later game when Muni starts rolling in, you can dedicate your CEs to placing these literally everywhere. Sweeping is completely out of the question when for example we are talking about 10 AP mines for a mere 70 Munis, placed all over the place, and guaranteed 1 model death off already numerically small Ost infantry and sometimes more.
Seriously. With this Commander try 2xCEs on dedicated AP mine duty. You literally cant place them fast enough to keep up with Muni income. Its quite hilarious and Ost will rage, hard, when whenever he tries to cap something or pass through a gap, he loses 1/4 of his unit for a mere 7 Muni.
This commander have only advantage in first 5-10 minutes. Have DSHK and this little mines. No arty, no armor.
Many wermach player only use blob. Simply put engineer in this blob.