Designing isn't about what is right and wrong, it is about achieving the look and function that you want. The full Persian chain maille is a 3D weave that has a wonderful texture. The aspect ratio you choose to work with will affect the look of the pattern.
A tighter weave with an aspect ratio of 5 allows the pattern to be rigid and shows off the rounded 3D shape of the chain. This tight weave can make the rings difficult to close properly. A really rigid chain can also pull the rings slightly open when it is moved as the rings push on each other so there is a point when a chain can be too tight to function properly.
As the Persian weave becomes looser with an aspect ratio of 6.25 and 6.6 you can see in the photo that these weaves still hold the pattern but the definition of the roundness of the chain is starting to flatten a little. The chain with the aspect ratio of 8.4 can't really hold the pattern and loses any definition.
The rings used in the chains in the photo are.
18g AWG (1mm) ID 5/16" 8.5mm AR = 8.5
18g AWG (1mm) ID 1/4" 6.6mm AR = 6.6
20g AWG (0.8mm) ID 3/16" 5mm AR = 6.2
18g AWG (1mm) ID 3/16" 5mm AR = 5