I agree with your sentiment (although they're not much more expensive to run), but I think you'll have a hard time arguing on the grounds of the drawing.
If I see my neighbour tomorrow I'll ask him.... He's a senior site manager for one of the biggest home builders in the country and responsible for a large development nearby. Will certainly be better informed then our friend Blowhardgreen.
These guys are under serious pressure to meet time
AND quality standards and the annual bonuses are contingent on performance, which include client satisfaction on hand over.