if you have ELite troops vet up the panzerwerfer to 2 stars and use Couter barrage mode.. watch those pesky katyshas die Its very hadny in 3v3 and 4v4 where katyushas bombard OKW med truck on retreats this will help counter it.
Mortar counter barrage is good but since soviets have more range they can use precision fire to hit your mortars its up to you.
(if you have arty filed officer you can use co ordinated fire to get 1 volley of panzer werfer even in counter barrage mode)