[From Bruce S. R. Lee]
There are several holes in the basic Chipco "Roman" army list -- some things are in that should be out, and you can't have other things that should be in (IMNSHO). The "Roman" list really calls out to be 3 or more lists.
Romans are really not a Fantasy Army, having too much "gravitas." However if you know where to look, there are some interesting or outlandish possibilities. While writing this it occurred to me that for "classical" armies, the nature spirits of doubtful alignment such as Dryads, nymphs etc would be mainly tricksters (nymphs) or traps.
Foot: Legionaries are all now HW/T, Aulilia are either HW/T also or skirmishers as Roman (Early Republic). This includes slingers etc. Small numbers of Archers -- I'd suggest up to 4 bases, only allowed to support other Auxiliary foot. Full time legionaries can be Elite HW/T.
More cavalry, much of it 'native' Heavy or Light cavalry with javelins, no bow. No more Battle Waggons, but lots of Artillery - Legions had a theoretical of one light engine per 100 men, and 1 Stone thrower per Cohort(?).
Small monsters = animals for gladiatorial games, thought about what to class gladiators as -- probably should be fanatics: very dangerous in theory but very fragile if fought correctly. Large Monsters -- ? Gog & Magog? say a pair of 'giants' ( I have a couple of GW Ogres that look about right in 25mm).
By this time Romans were picking up all sorts of interesting (weird) religious luggage -- "mystery" priests, Egyptian Wizards, early Alchemists; medicine was practiced with various degrees of success, in general the full spectrum of characters if you want them.