Sure, but as the article points out, that's not a great bound—and you really care about the expected number of tanks (or the upper bound), rather than the lower. The Allies had drastically overestimated this, by about fivefold.

Furthermore, the interesting part isn't just the number of tanks or planes—though that has obvious strategic uses too— but the insight it gives you into their industrial production. What's the limiting factor in getting a tank to the front--machining the parts? assembly? fuel? Which of our raids affected that?