I have to acknowledge that the comment above re TC is on target (no pun intended.) I did not take that into account when considering whether there were too many aircraft. Without TC, there would be far, far less, and I assume they would not pose a problem. The flip side is that it would take four years to complete a career! I guess I am stuck with both mods as is, as I do not see a way to circumvent TC unless I use Webster's Better Air Patrols. I have to think about whether I want to reactivate his mod.
Lurker, my apologies for not considering TC. It did not occur to me. TC is the culprit in my case, it appears.