Red,
I believe the arming device is incorporated in each individual round to be fired. So the numbers generated is the number of rounds - not the number of guns, per se. If the TO&E will be one weapon per squad, that makes 4 weapons per platoon, 4 platoons per company, etc.
Sure, the weapon numbers will be less than one weapon per soldier, or about 1 weapon per 10 soldiers, but next to small arms fire, this will be used quite extensively as a weapon of choice due to its accuracy and limiting exposure of troops to enemy when firing this weapon.
Further, 40mm is also employed in helicopters, and the rate of expenditure is significant. (We are looking at least 400 rounds per minute, for some variants of the traditional round).
This will generate a lot of numbers, IMHO, especially as it is incorporated in larger rounds as the Powerpoint presentation suggested.
Of course, at a cost of $35.00 per round, deployment ought to be more calculated and restricted than traditional rounds.