It makes sense to me, but someone who knows for certain will surely come along.
If you do end up using that type of filter, make sure to follow the instructions regarding how long the organic filtering component is good for after opening the package. Even if not exposed to high levels of contaminants, that part of the filter will gradually become saturated and stop working if exposed to the air. As I understand it, the particulate filtering capability doesn't have the same limitation, so you'll basically end up with a heavy P100 (or whatever the media is rated for) filter after a while.
Edit: Got ahead of myself - I am used to the 3M 60921 or similar, which does have a P100 component. I'm not sure what number cartridge you have there, but it looks different.