Lords
Bretonnian Lord
Heroes
Damsels
Paladins
Core
1+ Knights Errant
Knights of the Realm
Men-at-arms
Peasant Bowmen
Special
Questing Knights
Mounted Yeomen
0-1 Pegasus Knights
Rare
0-1 Trebuchet
Battle Pilgrims
Unsurprisingly, an Errantry War army consists mainly of young Knights Errant. Knights Errant are the only unit that counts for the minimum number of Core units in the army - ie, in a 2,000 points army, the army must include a minimum of three units of Knights Errant.
Grail Knights will often join the ranks of the young Knights Errant to give them some inspirational leadership - an ideal for them to aim for. Instead of taking a normal unit Champion, Knights Errant may take a Grail Knight as their Champion for +22 points.