Since Ripley said "but has a Karosthi" rather than "but has Karosthi" I am wondering if there is confusion on terms. Karosthi is a language: https://en.wikipedia.org/wiki/Kharosthi At the top of this reverse is a monogram that appears to be a backwards K and an E. Many cultures (including Greeks) used monograms. The Kushan kings each adopted a symbol that indicated his name/reign (remember the musician Prince tried this a few decades ago). These are called Tamga. http://en.wikipedia.org/wiki/Tamga By coincidence, the KE monogram looks a bit like a Kushan Tamga lying on its side. It most reminds me of that of Huvishka except for the latter's four bar E. Tamga of Kushan rulers of this period all seem to be a comb of three or four prongs above a base that changed with reign. Soter Megas had a circle; Wima Kadphises and Kanishka's look similar except the last tends to show the bottom legs grown together into something that looks to me like an inverted heart and the 'wings' turn down rather than up: Trying to describe these in words is not easy but that's why we post photos. Many Kushan bronzes are worn or corroded so we have to be careful but the reigns can be identified by these symbols with no other legend showing.
I agree Kushan is not indo-scythian. Kushan were the Yueh chi from the nw border of China, while the indo scythians were middle asian, (think southern russia). They had nothing in common save for being around similar geographies around similar times. It would be like saying Carthiginians were Romans.
Kushans rocked!! ... well, according to this out-standing Kushan statue (yah, I have posted it a few times, because it really does "put ya there, eh?"!!) => Kush-on, brother!!! ... woot!!