First, understand we don't use Staff Officer figures as such, as that can indicate what's coming to sneaky players. After a few games eexperienced players tend to look where Staff Officers are posted to see where the threats are. We use the cards in the rules.
Actually, I made my own to include the optional cards plus one for Divisional Morale.
I also included a value on each card so new players particularly can work out the cost in number of Staff Officers for each task. Initially it was a gripe amongst our new players that they had to look it up to figure out the coast of a Rally/Pinkerton/Artillery Assault etc. As an Aide de Memoir, I now include it on the cards.
So far I've allowed each brigade to place ONE face down Staff Officer Posting card. This could represent a fake, or up to three Staff Officer value task posting, obviously depending upon the nature of the card.
Thinking aloud though perhaps we need more as some commands could utilise more than once card?