I kind of agree, they are kind of useless... but however, for the people out there who cant aim (me).
Black Hand and Patch are good for taking out infantry, as they can usually kill a guy in just a couple shots at a fast rate(could someone tell me how many shots to the torso it takes to kill a soldier with a minigun?)... PLUS, they each get more health, which is always a plus on the battlefield. These units are not meant to take out tanks, so dont try it. In command and conquer, do you ever send out a minigunner, or chem warrior to take out some tanks? Not usually... Tanks are meant to take out tanks.
And by the way, 50 bucks more or less... 175 less... who cares? not like a big waste of money for someone who takes out infantry more quickly and efficiently.