One each of CGL (Light War Chariots), FL (Light Foot), CL (Light Cavalry) and S (Skirmishers).
I know there will be casualties, so I'm prepared.
Printed paper glued to washers. The casualty figures glued to magnetic sheets.
This pic may help anyone who wants to make such a disc. I'm not sure of its original source. I ended up putting it in Excel and sizing it and then replicating (copy and paste) and then printing and cutting out. The washer I roughed up with sandpaper and then smeared with PVA glue and put the paper disc on and it was done.