Okay. Stay with me, now, we're departing far from canon. This is just a crazy idea I knocked up as a conceivable backstory. Feel free to point out the holes, errors and inconsistencies in it, but I think it makes at least some sense. Warning - wall of text. Obviously.
Charlie learned of the Prediction that Wanda was fated to attune to an Arkentool. I don't think that's beyond his ability to learn. So he plotted and schemed to get Wanda under his control, knowing that she had no particular love for her side. He could have made an offer, like...turn to Charlescomm and wait to receive your Arkentool there, in return for, perhaps, Jillian. It would be trivial for Charlie, with Wanda feeding him information, to ambush Jillian in the field and capture her for Thinkamancy reprogramming or even an Arkendish-powered Thinkamancy-Turnamancy link, to devote her utterly to Wanda. Wanda always did want to control Jillian. That's one possibility, anyway, Charlie is good at finding incentives for people to do things. But Wanda's Loyalty to Banhammer prevented her from turning under normal circumstances. (I know Wanda claims she is only Loyal to Fate magic, but she could be wrong.)
Charlie watched Stanley find the Arkenhammer, and decided to seize the opportunity. Charlie spoke with Wanda and formed a plan wherein Stanley would attack Faq and be defeated, and the Arkenhammer would then naturally pass to Wanda. The power that the attunement would give her, Charlie explained, would enable to her to break away from Banhammer more easily. Wanda contacted Stanley, perhaps through Charlie, and arranged for the attack, without mentioning Charlie's name.
Only, Charlie was playing a different game. He wasn't going to rely on Wanda turning to him after she took the Arkenhammer; it would become nearly impossible to control her once she became a fellow artifact user. Charlie intended for Stanley to destroy Faq, and engineered this outcome through the careful placement of feral dwagons in the path he knew Stanley would take. He could have done this several different ways, but my personal theory is using a Lookamancer or a Findamancer the morning of Stanley's attack to spot feral dwagons popping in spare hexes and "convincing" them (perhaps through the same means by which Charlie is seemingly manipulating natural allies, putting simple orders into the head of a feral beast might be possible for Charlie) to move into Stanley's path during their turn at dawn. Charlie, naturally, told Wanda none of this. His endgame was to have Wanda be captured by Stanley and deny her the Arkenhammer, at least for now. Since captured units have very low Loyalty and Duty, she would be much more easily able to turn from Gobwin Knob than from Faq. Charlie would explain this aspect of the plan after the fact and renew his offer, adding that he would take the Arkenhammer from Stanley when Wanda turned (or unless Wanda turned...) so as to get Wanda on his side before attunement, when she would be much easier to control.
So Faq fell to Stanley, and Wanda allowed herself to be captured. Charlie contacted her afterwards, feigning lack of knowledge regarding Stanley's sudden strength, and explained the new plan to Wanda. She agreed to wait and encourage Stanley towards foolish campaigns, so as to attract enemy attention and warfare to reduce Gobwin Knob's strength until Charlie could smash the capital with one Archon-powered strike. This went well for a while, until Janis got the bright idea to try and break the rules of the world.
Charlie almost certainly knew about the engineering of Summon Perfect Warlord. His intelligence gathering capabilities would probably pick up something of this magnitude in the works, especially since I'd bet dollars to donuts that he has informants in the Magic Kingdom. Charlescomm never pops warlords...why is this? Well, Charlie doesn't really need them, given as his Archons can have leadership and certainly seem intelligent enough not to need warlords ordering them around. Besides, Charlie can communicate directly to any of his units with the Arkendish as much as he wants, so he has no incentive to delegate any authority to warlord units. It's at least plausible that Charlie considers himself to be so intelligent that he's not willing to delegate any battlefield authority because he believes that only he can effectively lead and direct units. He certainly does think he's super-smart.
But a perfect warlord? That's something even Charlie can get interested in. Especially if he could get that perfect warlord working for Charlescomm. Who wouldn't want an asset like that? And what better way to seize control over that asset than by controlling the caster Fated to cast the spell? This was a perfect opportunity; a target he was already planning to acquire suddenly gained enormous value. Charlie talked to Wanda about it, and she agreed to cast SPW for Charlie in addition to their normal deal. From her perspective, since she was getting the Arkenhammer out of it, who she cast SPW for wasn't tremendously important.
This fell apart when Wanda learned, in some way, of Charlie's treachery regarding Faq's destruction. Perhaps the casters Charlie hired for the plan had loose lips, or some faction intriguing against Charlie (the Great Minds?) sought to weaken him by depriving him of one of his pieces. Wanda was enraged not only that Charlie would deliberately deny her the Arkenhammer until she was firmly in his control, but that Charlie's destruction of Faq greatly endangered Jillian - the one person in the world she seems to care about. Even given that she didn't die in Stanley's attack, cut off with only her current battlegroup to stay alive and grub for upkeep as Jillian was, she was facing danger every turn. Wanda was incensed that Charlie would act so cavalierly, and decided to spite him by bringing SPW to Stanley instead of Charlie. From her point of view, she was going to attune to an Arkentool no matter what, so one particular plan falling apart would have no impact on her eventual acquisition of a Tool. Besides, only a perfect warlord was capable of extracting Gobwin Knob from the mess that she had helped put it in.
This explains Charlie's actions during Book 1, his polite interest in Parson and his eventual demand that Parson work for him. Charlie was severely upset when he learned that SPW had been purchased and he didn't have it. Making the obvious deduction that Wanda had taken it to Stanley, Charlie decided to wait and watch, idly signing on a few Archons with Jetstone just to keep communications flowing from the battlefield. Then he saw that Gobwin Knob gained a mysterious new Chief Warlord, who employed plans of considerable tactical skill - it doesn't take someone of Charlie's intellect to deduce that this was the Perfect Warlord he sought. Charlie tested the waters with Parson when Parson contacted him, playing cool and disinterested, seeking to confirm his suspicions.
It was the bracer that convinced Charlie. It's nearly artifact-level in its Mathamancy power - what could have created it but a super-powered spell like SPW, especially given that it's on the Perfect Warlord's wrist? So he sent in his Archons, bluffing to Parson all the while that it was only the bracer that interested him to make Parson think his life had less negotiation value than it did. Charlie made a fatal mistake in rising to Parson's bait and ending turn to watch the fireworks, as it lost him all his Archons. Charlie was now doubly pissed at Gobwin Knob - Wanda had betrayed him and Parson had humiliated him. This explains his current mania to stop Gobwin Knob, which is more fervent than the mere objective of tactical threat elimination would cause. Even the terrible fact that Charlie lost his Archons and all their secrets to Gobwin Knob hurts just that little bit worse since his beloved units are now under Wanda's thumb.
Whew. That's a whole lotta speculation at one time. But it's fun to think about.