unreason

Electronic subsystems like that can be refitted to existing vehicles without significant weight gain, and present no inherent advantage of the base platform. K2 also happens to use a much lighter and more sophisticated APS.
Why the Germans would decide on Trophy with even domestic alternatives that outperform it is just puzzling.
 
Which K2 achieves by leaving its sides completely unarmoured and copying the Leclerc bulge, which comes at the cost of a gigantic gun shield weakspot, as weight in armour forward of the gun trunnion is inherently limited by the need to have it balanced for stabilised fire.
When viewed from anything but 12 o'clock ahead, the unprotected bulge even presents a third of the turret target area, part of the reason why Leclerc fared as poorly as it did in the Swedish trials regarding protection.
 
Engine and transmission are of similar design, but the K2 uses much more compact and newer types compared to Leopard 2, especially if they intend to sell the new Doosan engine and the domestic gearbox, although both of those are taking their sweet time.
 
Nobody is talking about Poland anymore. That ship's just sailed.
 
That's assuming that they were so utterly stupid as to not mount any armour on the roof, which might well be the case for the North Korean glorified live targets that K2 is designed to fight, but even Strv-122 does that, and T-14's crew hatches are suspiciously thick. Such a small EFP launched from a distance shouldn't be relied on.
That you even have to think of such a creative way to approach the problem just shows how close the 12 cm gun really is to the end of its upgrade potential.
There isn't even any physical reason why other 12 cm gun platforms couldn't also use that ammunition, or why you'd even want a big, heavy tank gun just to lob velocity independent top attack munitions.

Why? What does K2 really add to justify the added expense of retraining and changing the stock of spare parts when both tanks are rendered obsolete by Armata?
At this point, it should be pretty obvious that the Norwegian and Polish programs aren't so much about acquiring a cutting edge tank for the next 20-30 years as they are about just barely keeping pace with the neighbours until a western tank with an unmanned turret becomes available.

Why? What does K2 really add to justify the added expense of retraining and changing the stock of spare parts when both tanks are rendered obsolete by Armata?
At this point, it should be pretty obvious that the Norwegian and Polish programs aren't so much about acquiring a cutting edge tank for the next 20-30 years as they are about just barely keeping pace with the neighbours until a western tank with an unmanned turret becomes available.