About your thinking to saw your models in pieces...
I have seen it before in a book or magazine, but i dunno what magazine it was
Maybe it was Military modeling but i am not sure.
There they filled the kit with pur foam
(i dont know if thats the English word) The isolation foam.
So the vehicle was much stronger and it was easier to saw it.. the foam could be painted later on.
Maybe somebody else knows the source of the article.
Hope this helps.