I finished the assembly of the 9 chariots last night. The riders are now all pinned and glued to the chariots, and the wheels to the chariot frames.
I've decided not to fix the chariots to the bases, yet, as basing will be very much easier without them in place. I have, though, used greenstuff to make ruts into which the wheels can be securely glued at the end of the process. I'm not going to add harness, though, as I'm worried about the fragile reins getting damaged in play, and because life is too short!