What time period?
How to get the most variation from a core group of miniatures?
For example; lets say I was to select Ancient Greece. I would have greek on greek or Greece on Persia. Great battles, interesting characters, ton of material available. Even if you included the colonial wars, Greece vs her colonies, your are limited in the strategies used. It is all Hoplite warfare. After a few games, my games, every game would become chess. A set number of opening moves with the out come not determined by one's ability to general the forces, but the randomness of the dice.
I was raised in Syracuse. I would love nothing more than to play out the Hoplite action around Syracuse on Sicily. Yet the time invest in painting all those hoplites for two opposing armies doesn't appear to have that return on investment. Once I am completely bored with the Syracusian affairs, what can I double down on? Persians? Athenians? Spartans? It is all Hoplite on Hoplite action.
The argument is for more variation. A high cross over usage. Rome has multiple enemy states with a large variation in fighting style/capabilities. If I am going to paint 2000 10mm dudes just for one roman army, they need to get some serious mileage.
But what roman army do you choose? A lot is about personal interest. If you are not interested in the time period, don't expect the project to last. I am very interested in the early Roman days.
Why early Republican Rome vs declining Republic vs Imperial vs death of Empire?
Death of the Empire; is out for me. I have zero interest in the declining Rome/Eastern Empire history. I don't care about the period it leads into. Arthurian Britain, Vikings, or the tidal wave of eastern barbarians.
Imperial Rome's; first 10 Emperors has great characters, large battles, and waves of barbarians. Afterwards I could give a shit less. In this period I feel, I would be painting individual army after army with little cross over in-between. Yeah the Cavalry could double across each horde. The meat rests in the Infantry. The largest block of dudes to be painted. Your looking at the Germanic tribes, Britain, Judea, Dacia, Parthian. Now how many of those infantry dudes look the same? Zero!
Declining Republic; I say starts around Gaius Gracchua and Marius/Sulla in the Jugurthian War. Why because mostly that is where the Roman army changes? The Marian reforms happened after, but lets say the change was in the works moving up to that date. After which point, most is roman on roman action. Maruis vs Sulla, Pompey vs Caesar. There is some Germanic, a lot of Pontus action, a lot of Gauls. Those last three enemies are very different, totally different with zero cross over.
Republican Rome; I purpose that same Roman army can be used from 300ish BC and the Samnite Wars to the death of Scipio Africanus (the younger) in 129 BC. During that time Rome was no less active, nor did Rome see fewer enemies.
( Is covering 180 plus years cheating the other periods compared to? I have divided the periods by changes in the structure/equipment of the army. The equipment used by the multiple enemies was about the same. The Roman army maintained the look until Marius started changing it. )
Rome was involved in Samnite wars, Prryhic Wars, Punic wars, Syracuse, Illyrian wars, Gallic wars, Macedonian Wars, Numantine war, Achaean war, Servile war. During that time the Roman army remained pretty much the same. The key is everyone they fought was pretty much armed the same.
If I were to paint this core block, Phalanx, Citizen spearmen, (everyone used) Gallic and Spanish mercs, Nubian Inf and Cav, Spanish Cav, and skirmishers. Those named would form the bulk of just about army in the listed wars. Then special 4 units to define the different personalities for each enemy.
Yet each opponent's composition was different. Prryhric Wars and the Macedonian Wars. Almost exactly the same core troops and warfare style, strategy and support elements were different. The war in Spain and the Punic war. The bulk of the fighters remained the same. Only the allied contingent changed. These small changes will prevent every battle from turning into a game of chess.
Add in unbalanced forces, historical fights, a non flat table and the challenge is ON! (it is a GW system but you are not forced to fight the GW way......matched point value, zero terrain feature, limited tourney scenario bullshit)