Our good friend Simon Miller AKA BigRedBat to those of us who haunt the forums, has written a fast play set of rules for the ancient period aimed at large battle. We have used them on several occasions for demo games now at shows. The link below takes you his site where they are available as a download and to purchase as a hard copy. We are stocking the hard copy now in our store.
He is in the process of adding army guides which will be free to download, below is the Polybian one