It will look for highest active provoke, passive will be ignored.

So if, for exp, you provoke with both WKN and Wilhelm, Wilhelm will get priority, given his 100% active provoke is higher than WKN 80%, even though WKN has a total of 110%.

In your scenario with Sieg, WKN, and Willy, Willy again has the highest active provoke, thus he is targeted.

In your final scenario, both Sieg and Willy have 100% active provokes, thus Sieg being first is targeted (this is interesting, as I wasn’t sure whether a second provoke would overwrite the first, but that doesn’t actually happen. What people used to call “overwrite” was proc order all along, so your result makes sense).