I guess Kraus covered it as well and so did several other texts in Fields and Waves class. A half wave element does not need a radial system to provide low angle radiation nor will radials improve it's performance. It can be grounded for lightning protection but the return path for RF is through the matching section. Look at a trailing ZEP, it did not need any counterpoise and the matching sections only return was the transmitter not the frame of the airship. You may want to check several articles on copper cactus J-poles. The bottom of the stub is shorted and grounded to a metal mast. The coax (with a choke at the feed point) runs parallel to the mast so which one carries the common mode current? how would radials improve it's performance? So I will agree to to disagree with you and you might also explain why a center fed half wave vertical antenna does not require radials but an end fed does and how it improves efficiency.