But, isn't it a bit loose? It takes 37.5k of "raw" ordinance but would call for over 10K less than "raw" damage inflicted? So the question is if its really "pure" damage why wouldn't it equal to the "raw" damage?
It's just using a different scale. The value for displayed damage message is is the inflicted 'lb' damage x0.64. So a town building that takes 312.5 lbs to be destroyed will yield up to 200 points for the landed damage message.
That may sound weird and confusing, but there is a simple explanation behind it: Internally the program doesn't use the "lbs" values we see in arena settings, but an internal variable of different scale. One "damage point" ~ 0.156lbs of "damage value" (the stuff in arena settings). A town building has 200points, a city square 540, The HQ 24,000. A 1000lb bomb has an internal 'damage point' rating of 6,400.
The "landed damage message" is simply based on these internal points. But the conversion is linear. Multiply the landed damage message by 1.56 and you get the applied damage in lb. (Which is actually simply 1/1000 the damage of a 1000lb bomb)
Some of the bombs in AH and their ratings:
(This table might also give a clue why I'm taking the allegedly 'puny' 80x100lb loadout for the B-29 when bombing the city...)