Very interesting vid on a controlled detonation of a 1000 kg WW2 bomb in Exeter (GB):

Drone footage shows WW2-era bomb being detonated in Exeter, England - YouTube

...allthough I definitely don't would like to be in any of the buildings around seen in the video, I find it nevertheless interesting that based pure on optical impression none of the buildings that stand even in the 1st row next to the explosion show any signifikant damage. 

So for me this confirms the arguments out of several other threads on that topic, that a 1000 kg bomb does not have a very big impact as it would sound based on the weight, so that 2x500 or 4x250kg instead are much more usefull against a group of buildings.

It seems that the damage model of IL2 with this respect is not too bad... 

It appears that the bomb is surrounded by some rectangular structures as well as being surrounded by mounds of earth, so much of the horizontal force would be absorbed and/or directed up at an angle once it hit the sidewalls.  I think this is why we don't see a shockwave or much disturbance in the nearby trees.  This is a controlled demolition of course.

But overall I think you are right that hitting a building with a smaller bomb (or bracketing it with a pair to weaken more sides of the structure) is more destructive than missing nearby with a bigger bomb.