My understanding is that Konami Kukeiha Club and Kukeiha Club are different entities, the one being just the name given to the sound team at Konami of the time—a team which consisted of many different composers/musicians over the course of its existence—and the other being an in-house band consisting of some of those members. I'm also not aware of KKC being credited for any arrangements—the whole team itself, that is. Those arranged albums were handled by one or two individuals each, I believe.
The Perfect Selection Dracula Battle albums, for example, were arranged by Naoto Shibata, and performed by his band which was called Naoto Shibata Project, which I believe was only a group of musicians he put together for these two albums.
Konami still has in-house musicians. They're just credited under their own names instead of the collective Konami Kukeiha Club.