Yes, yes, yes. There are grappling arts everywhere that result in pain for the "grappled". However, it IS the little differences that make these arts unique. There are Chin Na methods that I've never seen in JJJ or Bujinkan or any other grappling art that I've spent time with. Even the Small Circle Jujutsu that I've done didn't have the extensive coverage of finger manipulation.
Well I can't help the shortcomings you've run across or experienced in your training.
What I can say from first hand experience with chin na and with ju-jutsu is the method may be different, the technique unique or specific to "that" flavor of the day you're doing, but the ultimate lock, destruction, manipulation, pressure point, throw, drop, hyper extension, etc... isn't.