Flat out crazy
They are different sounding. I had a '96 Ram with a V10 and everybody that rode in it thought that Dodge made awsome V6's because they couldn't believe the power it had. Then I would let them know it was really a V10 and they couldn't believe that such a large motor could sound so mild.
It must be a firing order thing because I have owned in the past a Ford V10 in a motorhome and it sounded like a V8.
Chuck