From the announcement:
Utilising hit and run tactics, the new Early Egyptian and Nubian Javelinmen are ready to launch their next barrage.
With little to no armour, the Egyptian javelinmen will act as scouts, harass and launch short ranged barrages before re-positioning and launching another salvo.
Whilst primarily used for ranged and harassment, javelinmen are also capable of dealing with troops in close quarters. However, with a small shield, little to no armour and an improper combat weapon, make sure they attack the flank or rear for a higher guarantee of success.