[PlasmaKrab]

Apparently the Warrior's CG has been chaged class to fit that of the Rarden gun (class 19), which means that both should be able to fire at low-flying aircrafts (any hard data about it?), and anyway if one can, the other should be able too, as being coaxial.

Now about the HEK, I just checked and both have a HEK=5.
Are you sure you have the latest version? I've checked the 2.0 update I think, so possibly what you point out was a mistake that has been corrected since.
Otherwise, maybe that's something about the use (shorter or longer bursts) made of it in different classes fo vehicles.