Saying Triss is weak and submissive is ridiculous..
It's really not ridiculous, though. One of the things that makes these characters fun and engaging and interesting is that they've all got a tragic flaw, and Triss's real glaring flaw is cowardice. That manifests itself a bunch of times in the books, and while I think they did an understated job of it in the games, it still shows through really well:
- Wanted to flee at Sodden Hill, and again in Rivia when the shit hit the fan. Both times Yen slapped some resolve into her.
- Wouldn't stand up to Philippa or other powerful members of the Lodge in the books, even though she says herself that what they're doing is wrong.
- When the Nilfgaardians have her in TW2 she loses it before they even get down to the torture.
- In Now or Never, she's completely panicked throughout the whole thing. If Geralt doesn't show up, the whole thing is doomed.
Yennefer's flaw is that she's completely self-absorbed and the examples of this are numerous going back to her introduction in The Last Wish.
And in their relationships with Geralt these flaws manifest themselves pretty obviously. Yennefer will never, ever allow Geralt to win an argument with her, she
has to be the dominant force in the relationship. And Triss is too insecure to really assert herself, which makes her come across as weak and submissive when she's with Geralt (and she mostly is).