Lacking the will to do things properly is a known failing of other armies. He's not disappointed; being disappointed that your model of reality is correct is among the clearest signs that you've gotten things twisted inside. There are more practical matters to be handled regardless.

"Have the sunrise sword briefed you on the enemies we have been dealing with?"

"They said they took a lot more hitting to take out and that cold iron didn't help as much as it should have. Have you learned anything else about them?"

"Yes. The fundamental issue they failed to recognize was that our foes were not demons at all, but a tribe of Gargoyles. Many of them appear to have demonic blood or empowerment from the fiendish powers, which allows them to overcome much of their weakness to magic, but they are fundamentally mortal. This is why neither blessed nor cold iron weapons find purchase and smites manage only a partial stopgap. The surest antidote we have found, for organizations lacking in magic weapons, is that of a coordinated defense; they have little ability to strike at range, and if enough force can be concentrated it is possible to slay them between when they first dive for a victim and when they take off again. A lucerne hammer is ideal, when they can be brought to bear."

"I'll aim to get you some of those, then, if you don't have enough. And more arrows." And raid their base again; maybe she can kill a bunch of them and take some of the pressure off.

"My unit would find use for another twelve such hammers, arrows up to four thousand, and wands or scrolls of magic weapon up to five hundred castings; I will approve payment for their transportation from citadel Dinyar or purchase them from your stores at up to half again their Arodus market values in Absalom, under the authorization of Paralictor Regill Derenge."

She takes notes, though not anywhere Regill can see them. "Excellent. Is there anything else you'd like to discuss before I go get the second wagon? Or after, I suppose."

"Your crusade's campaign plans, or at least the public details thereof. It seems likely that operating completely independently is inefficient, and if nothing else we could press the demons in multiple places at the same time to divide their response."

"I agree. Do you have a suitable meeting room, or would you prefer to come back to mine?" Hers has the advantage of being able to easily grab her staff if they want additional heads, but if the Paralictor wants his own staff and maps and so forth or just doesn't want to bother with being teleported here is also fine.

"Our meeting tent is sufficiently secure for what I planned to share of our own goals, but it does not fundamentally surpass the second level of security; it's a static location inside the wound and not covered by a sanctum. Whether that is secure enough for your own purposes is something I cannot determine, but I am willing to join you if you deem it prudent."

After he sets things up to ensure the result of him being compromised is the order losing him for its purposes and not risking his unit, of course. There are some things you don't chance when taking an unplanned Teleport.

"Your tent is fine." She'll just not say anything it would be particularly bad for the demons to learn. It might not even be hard, with the much more imminent risk of embarrassment about Regill thinking she said something she shouldn't have.

Then they can head to the Paralictor's tent. Central location aside, it doesn't look any different from the tents around it, so either these particular hellknights avoid excessive ornamentation in their officers or the original was lost or destroyed.

They're both under constant observation on the way over, but not by the people who were keeping watch at the camp boundaries, and the new additions stop outside of the tent itself. They're not cleared for all possible things that could get discussed here, and if she is an infiltrator then the privacy might bait her into thinking it's safe to strike.

Still not an infiltrator! Once they're inside she lays out the crusade's broad objectives of taking territory from the current Wardstone line through Drezen and move the barrier inwards, and how far they've gotten. She doesn't mention the timing of their planned advance or say anything that implies the Gate trick is repeatable.

Regill spends the entire explanation listening intently and assessing. Drezen is an ambitious goal. Potentially disastrously so, if it fails and their army is destroyed far from Mendevian lines, but it at least has the twin virtues of being possible and worth doing if you could succeed at it. It’s also a sign that the crusade planning staff is primarily Mendevian. It’s too focused on symbolism over military pragmatism to be Lastwall’s work- they would have likely suggested making the crusade’s primary focus moving the fortress line up along the Sellen - and too bounded in scope for him to expect it from and adventurer who keeps their own council or esteems’ their party above Mendev’s strategists. 

That’s a good thing for the odds of the crusade staying on course, and bad for his ability to assume competence. It seems unlikely that someone with the ability to source exactly two castings of gate would blow them on taking Villareth’s Ford, which would suggest they have or can get more, but he can’t guarantee it’s not simply a catastrophic blunder. If they’re even being honest in their claims in the first place.

What are the ways the world could be? Call it three, for now. In one, this whole affair is a demonic plot, which is always a good guess for surprising events. It’d be an expensive one to fool the checks they underwent, and he doesn’t think he’s being lied to, but not impossible. In this world, he needs to ensure any changes to his plans don’t get his force killed for insufficient gain, and advantage any plotter obtains is worth less than faking it would cost them.

In another, they’re honest and incompetent, and absent a miracle thousands of crusaders are going to be killed uselessly. Regill has little sentiment for their lives, but losing the better part of the army of Mendev would be an unmitigated disaster for containing the wound. It would be well worth their entire deployment dying, if it meant they could preserve enough of the deployed forces that the wardstone line doesn’t collapse, and it’s his duty as a paralictor to ensure that happens.

And in the third, they’re honest and competent, with money and magic to burn and more gates where Villareth’s Fords’ came from. In this case, intervening here is an important opportunity to strike at the demons, and additional intervention might prove sufficient to actually achieve their goals or inflict disproportionate losses on the demons. It’s the best outcome, so he doesn’t trust it, but neither is it wise to ignore it. 

That makes his next course of action obvious. 

“A worthy goal. The order of the godclaw would be honored to contribute to this endeavor. I’ll make preparations to march north, either for Drezen or to disperse any enemy concentrations en route, and attempt to draw the attention of the Gargoyles away from your army.” Hellknights and Armigers are a much harder target than Mendevian conscripts for this kind of force, particularly if the resupply is genuine. “My adjutant will be at your disposal for the purposes of coordination.”

And then he’s going burn some scrolls to get into contact with Citadel Dinyar. He wants someone outside of the wound to do research on this alleged crusade, and also preferably some Signifiers with teleport in case this ends up being a situation where he needs to ensure the evacuation of Mendevian VIPs or their corpses.

"That would be much appreciated. I'll have my people talk to your people about prospects for further provision of supplies and establishing regular communications. Any more threats like the gargoyles shouldn't be able to surprise us both separately. Your redeployment is inevitably going to mean fewer men deployed down here; how much of a concern do you expect that to be?"