Kahunaburger: It would be an interesting spin-off. The one problem with playing a caster, I think, is how powerful they are in the witcherverse. I'm not sure how the game would represent their formidable range of spells.
Goodmongo: And yet Letho knew exactly how to take Triss out really fast. So a witcher seems to be able to defeat a mage.
Oh, yeah - it's not a "who would win in a fight" thing, which seems to be more a case of who has the advantage. It's just that mages have a lot more options than witchers in both the games and the books - they can teleport, create barriers, curse people, summon genies, paralyze with magic, create living things from nothing, and so on. So it would be hard to design a game that does justice to lore on casters.