I'm thinking of siding with Djikstra on my current playthrough. Three times I have always sided with Roche, and doesn't let Radovid to live because I want to protect the mages (Yen and Triss are mages too).
BUT, I don't feel comfortable with Djikstra. He didn't even risked his neck at the Battle of Kaer Morhen, which is why, emotionally, I feel the need to side with Roche, Ves, and Thaler.
Anyone who could convince me to dump Roche and friends?
I can't convince you.
But I never felt a strong bond with Thaler in TW1. He was just a foulmouthed fence and former suitor of Shani. He was also a suspect in my investigations for a while. Yes, I later saved his life, but if Geralt fell in love with everyone he saves, he'd never stop the wooing. Yeah, he was also a secret service guy and speaking for the sister buggerer Foltest later on. Good for him.
For Roche, it helps to be antagonistic at the start of TW2 as long as you can without getting shot by Ves. That turns the happy go merry buddying with Roche in Flotsam into something much more forced and unpleasant. Then go with Iorveth. Yeah, loyalty issues arise again later in Act II, when Roche saves your life. But you can shape this into a "he only did it because it served his own purposes", too.
TW3 allows no such thing. You could let Ves die in Eye for and Eye. That removes the obstacle of
"but Roche helped me at Kaer Morhen!" quite nicely, if that is the issue. And as for Dijkstra - recover the information about his treasure. He'll be much more favorable and, while still not risking his own life at Kaer Morhen or at the Poet Under Pressure, he will provide financial backup at both times.
It's also down to "what kind of person does it take to rule well?" thinking. Is it that shady ex-fence cobbler secret service guy, and his fiercely patriotic hypocrite (he kills Henselt, but he loves to throw the "Kingslayer" around as an insult. He hates to be called a son of a whore (because that's what he is), but it's his all time favourite insult, etc) - or it is that guy who has experience with politics and the brain to pull it off? And do you really want to be ruled by Nilfgard and that wifemurdering, incestoid emperor?
And one more question: Why would Geralt, who's not from Temeria and only went there by random chance in TW1 to begin with, feel fiercely patriotic about this country? So fiercely patriotic that it's more important to save this tiny part of the north while selling out the entire rest of it?
In any event: Doing a playthrough with choices you would never normally chose can be extremely entertaining.