Mathamancy was largely bunk.
Well, the catechism for the faithful of the Titans is "By Fate and By Numbers and By Luck". The three things that determine the outcome (according to Erf prevailing theory and faith) of an activity. Fate is the Titans Will, Numbers is the hard cold fact that bugle horned sheep do not win against dwagons, and Luck is the fudge factor that means its not just an exercise in applying such and such Archons at such and such time to win every time.
That statement by Wanda leads me to believe that she is more on the faithful end of the spectrum and less on the "reasoning" or mathematical end of the spectrum. She has given up everything she cares about (Jillian etc) in pursuit of her faith in Fate. I would imagine it would be very challenging to her sense of self to allow the other two factors much dominance in the grand plan.
Although, truth be told, statistics for Erfworld is a good way to go wrong with confidence. Look at the conversations about the bracer- math is only as good as the information you put into it. And every gambler counting cards or figuring the odds in texas hold em knows that, even when you are running at 83% to win, can always get screwed on the river. Still wouldn't dismiss it as largely bunk. I wonder if the bracer can do calculus of variations (almost certainly, given the plot related powers it shows, but only geeky math folks would care).
As for suggestions:
From observing the restrictions on other units with perceived range attacks, it may be that "archery" as a trait has more effect than just allowing one a better chance to hit with a brick thrown from a wall. Attacking across the subzones of a hex seems to be the real benefit- from ground zone to air zone, primarily. I base this speculation on the peculiar limits of the archons- laser beams that still couldn't be used to sweep the walls around Ansom clear of cheap undead.
So, it becomes important to extend the speculation to dragons. Archons have a check list of powers they gain as they level. Watching the dragons attack the siege in the first book, it seems that at least some dragon types can attack air to ground, perhaps as related to a 'archery' or 'strafe' trait they can gain as they level. Purple have siege class breath weapons, and reds have fire. I would hazard by its nature (cwap tends to go straight down) and the in comic demonstration of battle crap vs. parasol that the yellows can certainly target air to ground.
So my suggestion then:
Get the archons together to use their limited foolamancy. Obviously have to save Jacks juice for displacements on the core stack, so that archers are firing at the wrong people. As the archer stacks engage, and hopefully before they figure out where the primary stack is, send strafe units in to attack them. This has two goals- draw fire away from your primary group and limit the opportunity for any warlords to detect the true location (hard to look closely about the hex when you are dodging acidic battle poop).
To that end, Archons with leadership form as many stacks of strafe as is logical (based on stacking bonuses and how many leaders available). Last Archon or disposable warlord leads the sucker, er, soaker stack, which floats around low, looking like a juicy target, hopefully enhanced by foolamancy to that effect. Wanda, Jack, Ossomer, hot red head chick, and their mounts + whatever is left to fill their stack hide under veil, either very high, or above the soaker stack, or behind any plausible terrain (clouds, towers, etc).
The goal is to survive the turn by focusing damage on the soaker stack, killing archer stacks when and where you can. IF there is limited ammo capacity per turn (seems plausible), this would work out very well. IF there is no limit to the ammo of an archer stack, the strafe units become utterly critical- you have to kill them to stop them from firing.
Flash mobs don't seem useful, as they stopped vision into another hex, which doesn't seem useful when you are in the same hex. This strategy has a serious weakness against enemy fliers, who can circle and look for the veil while your units are playing with the archers, then swoop in hex or in subzone to attack when they spot something. Thus, it is predicated on the assumption that Jetstones air power is limited to the handful of unipegataurs and oreally's left, and not Jillian's force.