I recently read The Tower of Swallow and I seem to recall, that Kovir and Poviss had quite powerful mercenary army.

They did, and Povis (surprisingly) beat Redania and Kaedwen in the war that resulted in the Treaty of Lan Exeter, but victory in a single war does not make them the most powerful militarily.

True that, but they would not be a weak opponent for Radovid. And they would have the use of mages, who could be darn useful in war.

Absolutely. No argument from me on that point. Povis' true power is in its resources. That should never be underestimated.

Wow, that was a year and half ago. :) I almost forgot the topic. ;)

Honestly, I read Witcher books when they were released, so the fresh-most memories are somewhere like 16 years old and those the memories of Geralt being stabbed with pitchfork. Therefore I can't argue with you here, as you read books recently, and have better precise memories. No offence, but I'm not going to re-read them.

Anyway, if Radovid is beating Nilfgaard, which is undoubtedly is the most powerful entity in the world, I suppose that even after his losses during that war, he still could try to crush mages and wipe them out. With certain degree of Radovid's craziness and determination, that is.

Mercenaries are mercenaries and we all know where their loyalty lies. IIRC, Emhyr discussed that with one of his subordinates (no way I'm going to write that name, writing and spelling "Grzegorz Brzeczyszczykiewicz" is easier!) during the "introduction" scene in Witcher 3. So despite Kovir/Povis theoretical massive deposits, actual "cash" on hands they can freely allocate for that "trade" is up to question. Not to mention comparison between that sum and Radovid's coffers. Which are surely being low due to war with Black Ones, but Kalkstein's last hurrah said it all.

Mages of course being mages and all that, but being mages wasn't really helpful for them at the end if Witcher 2, where many of them were slaughtered by ordinary Redanian troopers. As far as I'm remember the insignia.
In addition, IIRC books correctly, there been one case mentioned, where mage was told to be nearly defenceless in close combat, as there is no way for him to ready the spells in time. So you don't really need an army to assassinate mages. And Radovid, apparently, has more than enough willing people for that job. But whether Tankred will be willing to allocate enough bodyguards for mages remains to be seen.

Or not, Witcher has ended, end of the line, please free the coaches, don't forget your belongings on your way out, our railroad line hopes you enjoy the ride and continue to use our services.
So far - hell, yeah!:D Because even with all flaws and nitpicks Wticher 3 is far better game than anything I played in years (Memories of Planescape are vague now). Gameplay is overloaded with unnecessary functions, true, but narration and story just redeem all that hands down, blindfolded, waist-deep in cold water, upside down, with fish in their mouths. Well, except New Game+ Armour mods, Ciriously, what the fuck?