There’s laziness and there’s laziness. Rino got into derailleur production by heavily copying SunTour designs - but at least they made a few detail changes and organised the production themselves (in Italy).
This, later, Rino model shows no such enterprise - it is a straight DNP model with the word ‘Rino’ embossed on the outer parallelogram plate. The pulley wheels carry DNP branding.
Technically this design is very derivative of Shimano’s original 600 designs. As such it lacks a slant parallelogram, and so is inherently less sophisticated (and is considerably heavier) than the design Rino were using a decade earlier.
One step forward and two, three or four steps back.