I've done this with success. I'd manually edit the text file.
There are multiple "player order knights" and sargeants. Editing 1 pair had no effect, another caused the unit to be treated as a companion somehow, but the third worked flawlessly!!!
I only edited items, proficiencies, and strength, didn't touch initial skills. It actually caused them to start with 8 available skill points, but no effect.
Keep in mind that items that require power draw or requirements won't be equipped until they're met. Also items not normally available for purchase for CKO won't show up in their shopping inventory ever, but they will use them in battle. (Eg Vanskerry shield or rune bows)