I just tested the difference in aircraft numbers between BH&HII and PE.

Unfortunately, the high setting in BH&HII has about half the number of aircraft versus the high setting in PE (not very high, or ultra high, but "high") for the same exact time and squadron. So, turning off the forced encounters will make most missions a milk run. I'm now forced to keep either medium or high setting to get encounters..... Not good. I wish OBD would have kept the same workshop settings and same number of aircraft during a campaign mission and not truncated it.