German Destroyers

[Tiornu]

The Germans went approximately twenty years without completing a destroyer. It's no surprise that the rapid construction that began in the 1930's would incur some problems, with a lack of time to correct those problems in subsequent classes. To compound matters, Germany's design bureau had never recovered from the restrictions of the Versailles Treaty. To put it bluntly, while individual German designers were gifted, the bureau as an organization suffered from inferior personnel. It's no coincidence that all German fleet units--from destroyers on up to battleships and carriers--tended to be either inferior or larger than their foreign counterparts. The Hipper class cruisers were 50% larger than the French cruiser Algerie but were not notably better despite the size difference.
The Americans built large destroyers mostly because of their Pacific commitments and because American had a hard time building anything that wasn't as large as possible. Here's an interesting gauge: by war's end, an American destroyer might carry as many as 500 5in rounds per gun or more; the British usually had about 250 rounds per gun; the Germans were content with about 120. The consequences of building for short range are seen clearly at Narvik.
I cannot agree strongly enough with Peter K's comment on the S-boats. They were wonderful boats indeed, and yes, probably the best surface craft in German service. (If I were to pick another type that neared the S-boats in quality, I would suggest the M-type minesweepers.) The key reason for the success of the S-boats was that Germany was way ahead of everyone else in developing light, powerful diesel engines. Even when other navies tried to directly copy the German practice, they flopped. Germany also hit on a very useful hull form that provided superior sea-keeping and stealth. Unlike the British and Italians, the Germans were not interested in small, expendable craft. They wanted something big and versatile, and they reaped the rewards of that decision.
I'm not surprised that a minesweeper would be referred to as a destroyer. Many sources don't bother with fine distinctions. The Soviets regularly referred to minesweepers as "M-class destroyers."
I can find only three Soviet submarines that were sunk by depth charges from any source. It woukdn't surprise me if no destroyers were involved. Hey, after the Norway Campaign there just weren't that many German destroyers left!
German ASW was exceptionally poor in terms of ships scoring kills. However, if you look at Soviet submarine successes, say, from Dec 1941 to May 1942... there are NONE. From Dec 1942 to Apr 1943, none again! And if you think it's just a matter of winter ice, check out June and July of 1943, or all of Nov 1943 to September 1944. The Soviets sat by and watched the Germans laying an intense system of mines in the eastern Baltic that completely walled off the Soviet subs; they sat and watched and did nothing to stop it. I'm sure there's an explanation for this, but I haven't found it yet.