As far as i know the COGAT is using a partial boundaries approach, where not all Palestinian villages’ admin boundaries are captured.
It is a disputed area, and I have never witnessed any “regular” admin distribution for the West bank area.
The Palestinians indeed have a normalized admin structure based on the former situation before 1967.
COGAT as earlier mentioned holds a partial admin area and if we take a look on Moetzet Yesha we see a full coverage of Israeli regional councils: http://www.myesha.org.il/?CategoryID=167
Considering the above, I tend to believe that as far as there’s a border dispute, admin boundaries cannot be considered for each side, as the other side will not acknowledge that.
Maybe an Admin boundary which is consisting on the built up area is the most precise approach?
The admin level 5 is at any case controversial as according to reality an Israeli settlement cannot relate to a Palestinian higher Admin level in my opinion.