Well, the idea is quite nice, though I wouldn't go as far as Konny did.
For me the Bruttians and Lukanians should be recruitable for Rome in her faction barracks during both Camillan and Polybian period; yet without restricting the AOR of "basic Roman units" like Hastati, Principes and Triarii.

We should bear in mind, taht during the period in which EB starts, the central Italy (Roman starting provinces) has been quite deeply romanized and filled with many Roman colonies, providing recruits organized along Roman lines. Regional troops should be available in regions that are to be conquered just after Pyrrhus has left Italy, i.e. southern Italy - Lucania, Bruttiom, Greek cities-colonies of Magna Graecia. However, I think that the recruitment has been quite well modelled in current EB due to government tree and barracks tree => i.e. when someone installs in Rhegium and Taras the "Homeland" at once it means that these areas has joined the Roman federation on far worse terms than those conquered before, and with heavy Roman colonisation of veterans - thus with heavy percentage of Roman units, with very litttle local units available (Samnites, Bruttians etc.).
On the other hand, removing the ability to recruit Camillan troops from newly conquered areas (Cisalpine Gaul and Southern Italy) is IMHO not as bad idea as it may seem => the Camillan Era has ended probably even before the start of EB timeframe, so the player should wait for appearance of new generation units - the Polybians.