 The brothers hired 20,000 Celt-Iberian mercenaries to reinforce their army of 20,000 Romans.The Romans strength had been reduced by losses sustained against the Carthaginians and Iberian tribes since 218 BC and the need to garrison the main Roman base at Tarraco.Observing that the Carthaginian armies were deployed separately from each other, with Hasdrubal Barca's army near Amtorgis; and, further to the west, Mago Barca with 13,500 men alongside Hasdrubal Gisco's army, the Scipio brothers decided to divide their forces.