From the file:
=====
Number Of Shield Levels := 4
Shield Level 1 Name := Normal Shields
Shield Level 2 Name := Phased Shields
Shield Level 3 Name := Plasma Shields
Shield Level 4 Name := Null-Space Shields
=====
So, what should happen is that the PPB first hits the phased shield portion, since it is listed first. It won't even consider the null shield points until all phased ones are eliminated.
Even if you reversed the order, you would still damage the phased shields. The PPB would first hit the null shields, and see that it can skip them. It then goes up against the phased shields, and sees that it can't. Its damage is then applied to the phased shields.
The ordering is such that regular damage depletes the worst type of shields (normal) first, so that future phased shots can still be blocked.
Assuming it all works properly in implementation, of course.
