"Republican Roman standard bearer confusion" Topic

In doing research for my Polybian Roman army (2 legions + 2 allied armies; in particular 220bc-160bc), I appear to be at a loss on what kind of standards should go with my signifers among other queries.

I know that some of the standards of Imperial Rome were in use at this time.

You have:
*Vexillum (cloth banners on a crossbar)
*Standards with disks stacked on top of each other
*Animal totem standards (eagle, boar, horse, wolf, and reverse minotaur) – one per legion
*Pole with a bundle of straw at the end (were these still in use?!)

Most of the information I found on the internet/books deal with the Marian reforms onward, so I am unsure where all these different standards should go. Should the animal totem go on the command base for one of my triarii maniples? Or did it stay close to the Legatus/Consul/tribunes? Are vexillum cavalry only? If not, what determined if a signifer would use a cloth banner or a metal disk one?
Would allied legions use the same kind of standards, too? Or did they use unique animal totem standards?

So many questions, I know, but a push in the right direction would be greatly appreciated!

I've copied and amended this from something I posted last year
"The bundle is a handful of straw. This is mentioned by Ovid as being used by the maniples (so the princepes and hastati)and the handful being the origin of the name. It may be accurate or some kind of folk etymology.

One theory is that the hastati and princepes weren't supposed to have a standard but an informal one was found useful.

By the first century, coins are showing standards with 'P' and 'H' plaques but there is no evidence for how early they were used – might be just a later thing despite the (presumable) reference to hastati and principes.

Pliny says "Caius Marius, in his second consulship, assigned the eagle exclusively to the Roman legions. Before that period it had only held the first rank, there being four others as well, the wolf, the minotaur, the horse, and the wild boar, each of which preceded a single division (ordines). Some few years before his time it had begun to be the custom to carry the eagle only into battle, the other standards being left behind in camp; Marius, however, abolished the rest of them entirely. Since then, it has been remarked that hardly ever has a Roman legion encamped for the winter, without a pair of eagles making their appearance at the spot."

The exact time of introduction of the vexillum and the way it was used are pretty vague. There is a summary here PDF link though it isn't really until the late 2nd century that it seems to be clearly in use. Livy mentions them being used much earlier, with the triarii, rorarii and accensi in each legio each having one, but this may be anachronistic. There are doubts about the whole passage e.g. regarding the accensi. The article I linked too seems to wonder if Livy is using vexillum in a looser sense than the 'little sail' type standard.

@Swampster

Thank you very much for that PDF! It certainly seems like there's a lot more ambiguity on the subject than I thought. I think I've decided on each infantry unit getting a disc signum, the Roman cavalry ala getting one vexilla, and the animal signum stands on the command base of the consul.