Knitting around the BIM corners

hello,

I'm making my first BIM steps (and I like it) BUT would like to use a real life example. Buildings are not always free standing and perpendicular (ahum). In this case the project is an attached building with crooked common walls on the left and right.
I find it difficult to model the corners using composed walls. In many cases parts of the walls need to be cut. My question is how will this relate to the of the volume of the ply walls later when extracting data?
Sometimes you will have to partly use composed walls and single ply walls. To me this seems to be a tedious task.

Attached is my 2D example with 'complex' corners (red circles).

My feeling is that in this case it would be easier to use single solids for every ply (facing and supporting walls).
Maybe use a composed wall for supporting walls + insulation (because this is in most cases attached to that wall) and another wall for the facing bricks?
However, then we end up with the window/door cutting through multiple walls problem, allthough there are workarounds...

Would love to hear your insights.

Thank you.