Actually teeth size is/was two fold.

Back in the day according to Pete Hamilton, you could order small teeth.

Note: Generally, small blades have small teeth.

During the Viet Nam war, when saw teeth were relatively high on the option list or knives standard with teeth were themselves high on the order list, i.e. the model 18, teeth seemed to get a bit larger or fewer per inch. Teeth take time, so the fewer teeth per inch, the less time.

Knives with teeth from the late 60's to early 70's usually have medium to larger teeth.

So, it is/was more than simply the wheel.

Here is a link to a post I did a while back comparing saw teeth on model 1's:

http://www.knifetalkforums.com/ubbthreads.php?