Rule of cool
Personally I would rather have a model that looked good than one which could hide behind stuff
Or if I were that bothered, I'd have the model removable from the scenic base and a second "game base" for it.
I have a number of scratch build models which are significantly bigger than the "official" model. 2 of my
DP's are about half again the size of the
GW model, and use massive wings that are about twice the size of the normal ones. I did that because I think they look better than the
GW models. They are easier for people to shoot, but thems the breaks.