Brain fade on my part. You're talking "incidence" and I'm spouting "dihedral". Duh!

The manufacturers (especially "way back when") did things simply because "that's what worked on the prototype" and not as the result of exhaustive testing at JPL or something.

Fhubers post is pretty much "on". He brings up a couple things I wasn't thinking about...That is, how to get a modicum of actual control over the model when using a single channel r/c unit. THAT was very common years ago. No elevator, no throttle, just a rudder that sometimes moved when you wanted. Some called it "r/c assist"....others called it "radio interference".

Trial and error, with a hint of Black magic...that's where a lot of that stuff came from!

Have fun!