mirror synclist update order

I have 2 Mirror SyncList<> lists - which are working fine apart from the order in which updates are received on the clients.

I want to ensure that one of these 2 synclists receives its updates on clients prior to the other one.

Updating the lists on the server in the correct order (the order in which I want the updates to occur on the clients) does not seem to be enough to ensure the same update order on the clients.

On the server, in the following order, I:
(1) add 7 item to SyncListA
and then I
(2) add 1 items to SyncListB

On the client:
OnSyncListB_Updated event is called 1 times
and only after that is
OnSyncListA_Updated event is called 7 time

How do I get SyncListA to reliably receive its Updated event before SyncListB ?

I discovered (by asking on Discord - thank you MrGadget and MegaMind), that the update order of the SyncLists is controlled by the order in the which the SyncLists are declared, not the order in which they are updated. Posting here, in case this is useful information for anyone else.