From: Vermont, USA
I've had two tries now on the Soviet Kharkov campaign, and while both have been great fun, I've lost the opening battle both times.
Have you tried it on "Easy" yet
My plan has been to destroy one or two German entrenched units on the main line of defense (the ridge), then pour through the gap with massive waves of infantry and armor (after a lot of artillery and smoke in preparation, of course).
This is generally a good plan, though I think you have to really clear one half of the map or the other to properly break through. Artillery and Smoke are key. Even trenches won't protect entirely against an on target artillery barrage by your heavier guns and Katyushas.
But taking those first two trenches always seems to require too much time.
Well, there's no real time limit, so you can take it slow.
I wonder: Should my tanks be firing APHE instead of HE at the trenches? What's the best Soviet technique for overcoming an entrenched position quickly? My battles have turned out more like WWI than WWII so far, unfortunately -- Trenches, machine guns, lots of infantry getting mown down or mortared while trying to advance over open ground, etc.
Move your infantry up in cover when possible. Keep smoke on the Germans in the trenches so that they either can't see to fire or are very inaccurate, that should allow you to get close to them without losing as much infantry. Use tanks in close support, but don't get within 25m (close assault) range of those trenches and foxholes. Instead, get within 30-50m or so and open up with HE, machine guns and small arms. At that range, the -2 firepower reduction that the trenches and foxholes grant will not be able to keep the German squads protected. It may take a turn or two of massed fire, but you'll eliminate squad after squad that way and eventually punch a hole.