Were the Bretagnes simply a second batch of Courbets?

Is it useful to think of the Bretagne class as a second batch of Courbets?

The machinery differences make that misleading: similar exteriors conceal different boiler and piping arrangements.

Calling Bretagne a second Courbet batch understates the machinery differences between the ships. Different boilers require different boiler-room and piping arrangements even where the exteriors look similar. The comparison treats the ships as individual engineering installations. Parsons turbines provide a shared component across those installations.