The Arveni Arjos (Arveni "Nobles") are disciplined elite soldiers, exhibiting great tenacity and proving themselves a sturdy force in any battle line.
The Arverni ("Superior Ones", home to the famous Vercingetorix) are a large powerful tribe who have become extremely wealthy through trade with the Mediterranean and 'exploitation' of the trade routes North. As such, the Arverni have a large body of Nobles afforded the time and wealth to prepare for battle. They also have the wealth to outfit their relatives and guards in a similar manner, allowing them to fight close by.
The Arjos (Ar-jus; "Nobles") sport the finest equipment available and train daily in its use. Due to their wealth and status they tend not to be as concerned with feats of valor, but instead exhibit greater tenacity in battle. Nobility in their class tend to engage in far less personal combat, and spend much more time entertaining themselves with feasting and games. However, in battle, like all Celtic nobles, when it comes time to fight, they tend to be very willing to prove themselves, and encourage their men to fight harder.
Though not the equal of the Greeks or Macedonians, the Arjos fight well in phalanx (similar to the hoplite phalanx) and prove themselves a sturdy force in any battle line, and they should not be commited to charging as often as other Celtic soldiers.
With sword and spear, these guys can take on either cavalry or infantry with amazing effectiveness. They are also well-armoured, important in the Celtic environment where almost everyone has a javelin to throw. In a shield wall, these guys will hold off almost anything, while they make excellent troops for reinforcing a line at weak or critical points, to make sure you win where you need to.