There is a defense platoon that is the standard all around. They get 2 additional commisars to use and seem to be able to include all the minis release up until this point.
The political platoon is led by the commisars and can have an extra air transport for additional support. same structure as the defense platoon just different leader and support.
grenades are great. only 6" range but when your entire army can make mince meat out of a tank its a good thing.
I was playing some of the cc squads with the transports today and OMG it was badass. I can move 36" then deploy the cc squad in cc and get another 6" with their attack. AMAZING!!!