Hi,
In that case, I would advise against having too large geometry collection, for large building and if you want detailed destruction , they may be expensive and a single cluster may produce a lot of sub-pieces which will put pressure on the physics solver
Since your buildings seem to be made of repeatable patterns which hopefully are their own meshes ( like the arch door for example ) , I would recommend making a geometry collection per element and still use the root proxy to render them while they are not yet destroyed ( this way you benefit from lumen , LODs and mesh instantiation if needed )
Hope this helps