Is it really necessary to have such low landing gear on stunt ships? Can't we just and length and then trim out the extra drag or weight some how?

When it became necessary to start flying off grass due to loss of any paved flying sites in our area we had to adjust by 1.  lengthening the gear  2. use larger diameter wheels  3.  go to a little heavier and better mounted gear.  The best way to deal with it is to NOT make the gear any longer than we had to and use the lightest weight/ lowest drag wheels we could find and also keep wheel pants, etc. , as light as possible.  Even so most of my airplanes require a little bit of trim to offset the vertical CG issue in the form of small trim tabs built into the wing flaps.   Obviously these are more or less effective with changes in airspeed but I've not found that to vary enough to be noticeable since the trims aren't twisted out that far.  I think the variance of engine torque for our monster-sized competition motors is more an issue and so happens to twist the airplane the same direction so the trim tabs are compensating for the identical ailment...shame they couldn't counter-balance each other - with IC.   You likely could with electric since you can choose motor rotation direction.

Dave