Here's one, from experience with the Global Hobby "Tequila Sunrise 40" ARF. It's a nice looking plane, aerobatic and all that, but putting it together was a surprise.

When I went to put the wing in place, I found the standard aileron servo would interfere with the elevator & rudder servos. In order to eliminate the interference, I had to (1) buy a low profile servo for the ailerons, and (2) use a short servo arm. Of course, I didn't spot this up front, so there was a delay and some fiddling around while I got the servo and figured out the short servo arm requirement.

So, in that case, it would have been a good idea to design the wing with two servos rather than one in the center. In other cases, where the available room in the fuselage is minimal, the same may apply.

Best wishes,
Dave Olson