Purple Worms Without Handlers or Commanders [D@W]

Due to some absolutely wild results on my weekly borderlands random encounter check, a NPC realm adjacent to my PCs main theatre of operations (Muntburg) is being invaded by a full-strength herd of 4 Purple Worms. One of my players just bought D@W and is eager to try it out, so I decided to set up a battle and let him play the Legate of Gloris and his 6 infantry platoons.  However, since the opposing side has no general (or officers...or any brain cells really), I'm not sure how to play them.  Should I build them as Independent Heroes? Being monsters with 9+ HD they qualify. Alternatively, should I consider each one to be a "division" and its 'own commander'? This would probably kill their initiative, since I can't see mindless eating machines having a strategic ability higher than -3, and just seems weirder than building them as Hero units.

If I do build them as Heroes, will they be forced to engage enemy Heroes first? That is my reading of D@W:Battles, ch 4 ("Heroes tend to seek out the glory of man-to-man combat. Therefore, a hero may not target an enemy unit if there is an enemy hero available as an eligible target"), but this seems counterintuitive for me, since Purple Worms are perhaps the quintessential "eats a bunch of mooks each round" monster.  On the other hand, what's more heroic than a Hero throwing himself between a ravenous maw and his hapless men?  On the other-other hand, now that I'm considering it, I'm not sure if that passage applies to targeting all heroes, or only independent heroes (and I know my player is planning to deploy all his Heroes initially attached as commanders and lieutenants). Clarification on this passage would be greatly appreciated.

Best of all, when I randomly generated magic items for the Legate of Gloris following ACKS Core pp 248, I rolled him an Apparatus of the Crab. How the heck should I build that as a D@W unit?

200 HP = roughly 45 HD = 3 UHP (which will be quadrupled since we're at platoon scale and this has to be a Hero); AC 10 (0 is clearly an error coming from 1e AD&D) converts straight over, the movement is all wonky but can just be treated as 1/2/3 I guess. Since the attack throw depends on the pilot, that would be variable but since it's a straight conversion, no big deal. Converting #of attacks, damage, and cleave factor is where it becomes a mess. It doesn't help that the item description looks like a mangled  copy of the AD&D 1e description of Apparatus of Kwalish and is highly confusing to me.  AC 0 is clearly meant to be AC 10 in ACKS, but the "if a hit is scored, there is a chance that both pinchers strike, for a total of 4d6 points of damage (roll of 1-5 on 1d20)" passage doesn't fit with the apparatus being given 2 attacks? Is it a chance for bonus damage? A chance that if one hits, the other will do damage even if the attack throw failed? Ignoring that passage for simplicity, it gives me 2 AT for 2d6/2d6, at the pilot's attack throw (and presumbably cleave factor). That yields (2 + pilot CF) * (7 * 2 / 2) / 45 , then x4 for platoon scale. Since I know the pilot will be an Epic Hero, it becomes (2 + 2.15) * 7 / 45, which works out 0.645, rounding up to 1 unit attack at company scale, and 4 unit attacks at platoon scale.

Anyway, it looks like my first ever foray into running D@W will be an anime-style battle between ravenous kaiju, hapless soldiers, and an heroic mecha! Any thoughts on how to build & run the Purple Worms, clarification on whether Heroes must engage any Heroes first or only independent Heroes, or insight into just how the apparatus is supposed to work would be greatly appreciated!