Just seen a YouTube video of someone in the Uk receiving the above battery , anyone else have theirs delivered yet. Seems to be an issue where the required cables aren't included.
https://www.youtube.com/watch?v=ujjeSVWUIBs&t=6s
9.5Kwh battery now being delivered
I see no reason that the 9.5kWh battery would have to be connected directly to the inverter as the first in the chain. The RS485/Modbus doesn't care, so long as master and slave addresses are correctly configured. The DC current is limited by the inverter's capability, so that isn't an issue.
As to provisioning of the cables with the batteries. That's been apparent on the wholesalers' sites since they were listed for sale.
Sound's like someone didn't do their research correctly.
The cables need to be ordered separately. I believe the cables are 1.5m length and cannot be lengthened or shortened by the installer.

Assuming all the batteries charge/discharge in unison to an even % value, then it makes sense to me to have the largest battery (highest current) on the shortest cable wired to the inverter.
The other way round would probably skew the voltage readings on the smaller battery due to volt drop values on each battery cable, and potentially lead to inaccurate state of charge values.