I've played with the leading edge slats on a full-scale Bf-109E.. these move with finger pressure, in and out.. Expecting a model with free moving slats like this would be practically impossible to construct.
A servo is required. but as for the utility.. probably not much. The models tend to have high wingloadings, which require keeping the speed up anyway. Any attempt to fly one slowly ends up in the garbage can.
On the Ford, it might be more practical to have them working.. but the mechanism MUST be reliable on both sides. If one side sticks, the plane goes into the garbage can also.
These kind of sliding mechanisms can be difficult to accomplish in model sizes, friction is a big problem. Simulating the slats by hinging instead of sliding would be more reliable, but less scale-like.
The trimmers would be something else to distract you in flight. You have only so many thumbs...
The Flanker slats/brakes could be a handful also, requiring some mixing of the elevator to control ballooning-diving when they extend-retract.
One -or- the other is practical, but both might be a handling problem.