Here is a quote from Soares based on your described installation...
"If the installer chooses to, an individual grounding electrode conductor may be installed from each service disconnecting means enclosure to the grounding electrode.
In this case the GEC is sized for the service-entrance conductor serving that enclosure.
The code does not specifically address or prohibit this concept but it is similar to connecting taps to a common grounding electrode conductor. In this case the taps are connected directly to the electrode."
shortcircuit
