they're 235(230?)mp; they're going to lose to any baseline squad most of the time. they have grenades though, are cheap to reinforce, get schrecks, and can build cover. they also get insanely tough with vet. they're really more of a utility/tanking unit but they can still deal damage, particularly once they get vet and hit with nades.
This.
Early game trade with who you can, troop losses are okay but DON'T loose squads! Try to piar your squads. They vet well doing damage to armor so go easy on nades as they delay your shrecks to counter things like M3.
Mid game deploy them as support for your light or medium armor. A Jagd or PIV supported by a couple of Shrecked up Volks and you can watch your opponents armor crumble.
Late game, Move to deploying Panthers and even Heavy armor, again support with Volks and possibly Obers.
Whatever you do don't blob! You can win games faster and with more skill by not blobbing. Never have more than 3-4 Volks at the same time, unless you have no other options. Its a waste of Pop-Cap.
Playing as OKW without blobbing will earn you the respect of your opponent. As well as many other players.