German döner is genuinely different from either Turkish döner or shawarma: It’s bread with kebab meat (or something similar to kebab meat, but made from cheap meats and filler content), onions, tomato, cucumber, and pickled white and red cabbage and a sauce (this varies regionally, e.g. we have the trifecta of joghurt/herbs, garlic mayo, and sweetish chili sauce).

[Oh, and the kebab meat itself can also be replaced with, most commonly, falafels (“Falafel-Döner”), or in some cases, seitan. But even if you stick with meat, you can usually choose between cow and chicken, with the original sheep meat being the rarest option.]

The way I see it, shawarma comes in strips and kebab in flakes

Not true:

The result is the trinity of kebabs, gyros and shawarma

Drunk me heading to AbraKebabra right now.