Obviously, yes. The Inquisitors are not Sith, so by definition they are then Dark Jedi, because Dark Jedi is anyone who uses the dark side but isn't affiliated with the Sith.
Timothy Zahn invented the term Dark Jedi to describe dark siders since I don’t think the term “Sith” was used in the OT. Zahn didn’t know what to call dark siders like Vader or Joruus_C%27baoth so he went with Dark Jedi.
It’s not really accurate though since they really don’t have anything to do with the Jedi. Zahn himself has gone on record and admitted it’s a little outdated.
I’m not denying your explanation of what Dark Jedi are is accurate, I’m just saying I don’t think it’s an appropriate term to use anymore, for the Inquisitors or any non-Sith dark sider, given that it was a term born out of necessity rather than accuracy.