Myself, I "abuse" the system by hiring hundreds of soldiers to screen out for Psi >= 90. Then I fire whoever is less than that, filtered using StatStrings.
I see this as what the HR dept. ought have done it before reaching my "desk", like it is done in Apoc. The only drawback at the moment, if any, of this mass hire and fire is the soldier IDs are in the high four digits easily.
(What was the shortcut to mark for sale everything that the screen shows?)
I'm not sure if I'm 100% correct code-wise, but I'm thinking the following:
As per hiring process, one could hire different type of [human] candidates (rookies, veterans, etc). Then a free, attribute-less transformation (call it "workplace induction" if you must) would convert the soldier from candidate to agent, to which all the other transformations could occur.
Alternatively, and I'm not sure if the transformation code would work this way, additional transformations (at a cost, both money and in time) could be included to bring the soldier to a higher stats, but only to a certain max.