Give 'em more fighting power, if just slight enough to do a significant difference at all. It's really underwhelming in the missions where you rescue four knights and stage an assault, only to realize that your own attacks are the ones that really count because the rest is blatant cherry tapping.

Make them more conscious of their shield as well, I never see them raise their shields. It really hurts to see knights with a Mighty Defender only to see that they never learned how to hide behind it in the first place.

And also, allow them to pick up mineral deposits so they can add to your total. That would give mecha knights a lot more useage and in return making collecting minerals easier for both constructing gates and feeding sprites, especially in a time when sprite maintenance is hindering gate constructing activities. I mean really, why wasn't that done in the first place?