It’s a best practices kind of thing. It’s not to say that you cannot do it, but it’s just not the best way to go about it.
So for something where you’re doing some line traces and you have overlapping collision hulls you may be more likely for it to read the wrong collision hull in that type of instance. The more collision hulls you have in your scene or even just on your mesh will take away from performance. So by optimizing and keeping hulls from overlapping you’re preventing the wasted use of these collision hulls.For some assets it may not matter as much, but something where you wouldn’t want to risk that miscalculation adhering to the suggestion in the documentation would be best.