The classification of submersibles under Harmony class and Jiaolong class appears to be primarily focused on their roles and depth capabilities.

Harmony Class:

The Harmony class submersibles include:

• Harmony: Often referred to in various sources as a predecessor to the Jiaolong class. It became known as Jiaolong after achieving certain depth trials. (source)

Jiaolong Class:

The Jiaolong class submersibles include:

• Jiaolong: This is a Chinese crewed deep-sea research submersible capable of diving to a depth of over 7,000 meters. It was initially known as Harmony before completing its 3,000-meter class trials and subsequently deeper dives. (source)

In summary, the Harmony class appears to include the initial design and trials of what would evolve into the Jiaolong class, with Jiaolong being the only classified and operational submersible within its class as of the current information available.