I've also abandoned nails holes as not being realistic. Also, the butt joints should fall over the studs, which on your wall do in most cases but some don't.
I like to cut my own butt joints, depending on where my stud spacing ends up; sometimes 16" OC, sometimes 24" and sometimes something else.
If I ever add nail holes again, it will only be randomly and definitely not on a painted wall.
I do like the siding though.