Lighter machinegun team with more guys? It has 3 the exact same ammount as MG42 crew. Plus PE MG42 comes with 4 guys instead of 3 and they carry PE rifles which is better than the MP40s the Wehrmacht one comes with.
They do not need to be set up. Its a mobile and more fluid play style. I would pick Support Grens if I'm playing aggressive and MG42 if I'm playing sit and shoot.
Different units for different jobs.