Fast cruisers as surface-raider pressure

Could very fast six-inch cruisers have been a more useful German Atlantic-raiding force than pocket battleships?

Yes. They could be produced and supported more easily, escape through northern waters, overpower convoy escorts, and force Britain to divert scarce cruisers from other theaters and missions.

The proposed raider is a roughly 40-knot cruiser armed with six-inch guns and enough range to reach the Atlantic, potentially using the Norwegian coast to help break out. Such a ship would be easier to maintain and support forward than a Panzerschiff with eleven-inch guns, while still carrying ample firepower against merchant vessels. Its purpose would be to attack the convoy system rather than duel British capital ships: a cruiser-level raider could overwhelm sloops and escort destroyers before a defending cruiser arrived. Britain would therefore have to attach scarce cruisers to more convoys or accept greater risk to the escorts. That diversion would weaken Mediterranean forces, global presence missions, task groups, and screens watching for heavier surface raiders.