Well, post BG there are a few things I see differently from before. KoTC and the Denarians are just one of them.
One thing I notice is the fact that Marcone has been holding and using Namsiel's coin for years now and the KoTC has not even reacted. No mission from above, no divine revelation, nothing. Assuming that Marcone has not done any bad things with this power all this time, I doubt anyone would believed it. This should tell us something.
Previously we are told that the KoTC are there to balance the coins, but with the example of Marcone above this assertion become somewhat doubtful.
There is a line in BG where Harry told us his insight about how the holy swords operate, and this insight led me to think that the KoTC is not there to balance the coins. At least that is not their most important job. Their most important job is to ensure there is a choice to be made, not to undone or to prevent the harm or damage by the denarians or the fallen inside the coin.
This should grant us a deeper understanding about why KoTC gave different treatement between those Denarians completely controlled by their fallen and the Denarians actively cooperating with their fallen. For those completely controlled by their fallen i.e: Rasmussen in book 5 for example, A KoTC can kill them directly after giving a few wwarnings. Basically this people no longer able to make a free will choice, so killing them and saving them does not make a difference. It can be argued that killing them is in fact saving them.
For those like Nicodemous however, they still make free will choices every second of every day. Their choices could be evil but they are still choices. The KoTC's job is to present them with alternatives. Chances to take a different path. Killing them is never an option to begin with. If we ever imagine that Nicodemous is going to be beheaded by ammorachius, it is not possible in my opinion. Killed by Harry's magic is possible, but directly killed by the strike of a holy sword is never goint to happened.
Another thing is about the path to *Monsterhood*.
Basically, *Monsterhood* in itself is not evil. Mab is a monster. Marcone is a monster. I bet the original Merlin is a monster too. Unless you choose to stand by and do nothing like those people in the white council, you are going to end up as a monster sooner or later. And the white council has the blackstaff as their pet monster, so I say the WC is monster by proxy.
Another point is the fact that monsters has their place in the DV. They have their role and their role are vitally important. This is why the coins are meant to be circulated and any attempt to completely seal them and kept them from circulation will eventually end up in futility. This is because as the KoTC is there to open the alternative to light and redemption, the coins need to be there to open the alternative to darkness and temptation. Only when they are both there would "Free will" has any meaning.
This meant, a holder of the coin is not nescesarily become the enemy of KoTC. A coin holder will only encounter a KoTC in their official capacity if there is a point in time where they need help to make a choice.
Under normal circumstances, coin holder can make choices on their own. The fallen can tempt them, of course. But as Harry show us, a person will can always keep the fallen's influence at bay. In the end, it is the person's own choice that must determine everything.
Sometimes however this balance is broken. Even the best people has their limits. Harry in BG and Michael in the short story is a classic example. Or sometimes the fallen inside the coin cheated and exert more power or influence than what is strictly allowed. In such cases, the KoTC is deployed.
If the fallen inside the coin play by the rules and there is no extenuating circumstances, TWG won't call upon the KoTC. This could explain why Marcone is never disturb by the KoTC. It also explain why only 3 knights is needed to balance 30 coins.