I am going just a little bit to contribute of light on the personage of Sertorio and reasons for which it does not have to be leader of any Iberian faction, in any case like Roman special unit. His biography in a better english:
http://en.wikipedia.org/wiki/Sertorius
1. - This man killed many Iberos. When by order of blunt the pretor Didio was sent to Spain along with, they lodged in a celtíbera city called "Cazlona" (Thamis another city more), where their soldiers incurred offenses to the inhabitants of the city which requested aid to the neighboring city "Orisia " (Thamis another city). Secretly the soldiers of Orisia and Cazlona entered the city and marries according to house went assassinating the Romans who as much had offended to them. Sertorio escaped and its revenge was received assassinating to all the inhabitants with age to take arms of the two cities.
2. - He was a politic man, simply settled down in Spain to have a refuge for his political friends in Rome (where its situation was very difficult). Let us remember that it was in favor of "Carbon", and was "Sila" the one that governed in Roma.Arrived here and rearmed the Romans.
3. - One became general of the Lusitanos, when these requested military board to him, since Iberian didn't have generals. Their ruses to gain the esteem of these (not very contentments with having a foreign general) widely are known, is famous their ruse with red deer:
One Iberian called Espano, who lives in the field, meet with a baby deer that fled from the hunters; and to this one it let it go; but to the musk deer, astonished at its color, because it was all white, it persecuted it and it reached it. Was accidentally Sertorio encamped in environs, and as it received with affability to which they took some present to him, or were of hunting, or of the fruits of the field, compensating with generosity to which therefore they did flattery to him, this one also appeared to him to give the musk deer to him. Accepted it , and was not great in the beginning the pleasure that declared; but with time, having itself made so tame and docile, that it went when called it, and it followed to him anywhere that it went, without being frightened of the bustle and military noise, little by little was divinized, we say it it thus, making think that that deer had been a present of Diana (a God), and scattering the voice of which revealed the hidden things to him, by knowledge that the Barbarians are naturally very inclined to the superstition. In order to credit it more, it was used this means: when reserved and secretly it got to understand that the enemies were going to invade their territory, or tried to separate of his obedient to a city, he pretended that deer had spoken to him in the hours of the dream, coming up to him that he had the troops to point. On the other hand, if warning of which occurred him some of its generals had reached a victory, hid to which it had brought it, and presented/displayed to deer crowned like announcer of good new, exciting them to be glad and to sacrifice the Gods, because shortly fausta had to arrive one the news..
4.- Since we have commented Sertorio were a politic man and it used to the íberos in the internal Rome fights (winning its affection with gold and ruses). The battles disputed against other Roman factions are multiple. It died assassinated..