The Irish do get Spearmen and Armoured Spearmen. With the high upkeep costs (compared to "native" troops), Spearmen are worse than useless to the Irish, but when facing Huscarles (and heavy cav), Armoured Spearmen are great for pinning and holding while the Gallowglasses and Kerns move to flank.

With the native troops, proper terrain usage is a must. Archers will outrange you, and cavalry will decimate you, so trees are your friend. Your troops are light and fast, so use this speed to tire out the enemy and gain the high ground.

Welcome to the Org, Jamie the Shrubber.