Romani Regional Legion units

[Ibn-Khaldun]

I wonder what are the best units to use as Romani in Gallia, Iberia, Greece and other places??

My legions usually have 2-3 hastati, 2-3 principes, 1-2 triarii, 0-1 equites.
But now I want some regional troops to support them. What are the best units for that??

Currently I recruit Teceitos as my infantry auxilia in Gallia and Archers and Slingers as missile auxilia.
Is there a better unit I can use instead of Teceitos??
In Iberia I have Milites as my main auxiliary unit and some Balearic slingers as well. They can do miracles if used properly.
In Greece and Mikra Asia I actually use mercenaries. Celto-Hellenic Hoplitai, Mercenary phalangitai and Cretan archers are units that I use. Are there better ones??
In Africa I use also mercenaries and Numidian Cavalry too.

Also, how should I balance them properly to get more 'real' army composition?

[Atilius]

Small numbers of foriegn military specialists were often found in Republican armies once Rome had expanded out of Italy. But there is little connection between the places they were raised and the place in which they served.

Just a few examples:

• Polybios (3.75) mentions 500 Cretan archers and 1000 light infantry dispatched to Rome by Hiero II early in the 2nd Punic War.
  
• At the beginning of the war against Perseus in 171 BC (Livy 42.35), arrangements were made to raise 2000 Ligurians (at least some of which were probably skirmishers), some Cretan archers, Numidian cavalry (supplied by Masinissa) and elephants from Carthage.
  
• Sallust makes reference (JW 38) to Ligurian infantry and Thracian horse during the Jugurthine war.
  
• In De Bello Gallllico, Caesar mentions Gallic (1.42) and German (7.13) horse, Numidian and Cretan archers and Balearic slingers (BG 2.7) in his armies.

One thing we don't really see much of in Roman armies is non-Italian heavy infantry.