I answered your question here with relation to the Anglo-Saxons, and the short answer is that yes, skirmishers and javelineers played an important role in Anglo-Saxon warfare, and are attested to in sources at the time like the Anglo-Saxon Chronicle's account of the Battle of Brunanburh and the poem The Battle of Maldon.

Although the central aspect of Anglo-Saxon warfare is the warhige or spear wall, javelineers (and implied archers, although less certain) operated on the flanks and to the rear, hoping to disrupt opposing formations, to either break a charge or to disrupt an enemy shield wall and allow a charge from their side to hit home more effectively.