Interesting. I am familiar with Ackerman as it applies to an auto's steering (as applied to cornering geometry and such) but in over three decades never heard it in an aviation discussion (full size or modeling). However, I think I see your point in using it, say from a "toe in" point of view, because of the geometry of the cabling and the offset (movement) of the control surface (whether it is vertical or horizontal really.) It is not easy to calculat if one is not familiar, but the idea is not difficult to imagine or comprehend on a smaller scale. And sorryif Iintruded on the thread;but being familiar with pull-pull as old pattern flyer (and I saw it in use on elevators in the late seventies)I think bringing up Ackerman was a really good idea and a way to correlate the actions of the pull-pull set up. This pic is a pretty good description of it if you envision the rear axle as perpindicular to the fuselage center line looking aft . I hope the pic displays ok, if not my apologies guys.
Hook

(from a Bimmer site)