 Almost immediately effort was focused upon selecting and identifying the officers and NCOs . To this end volunteers were called for amongst units that had already formed as part of the 2nd New Zealand Expeditionary Force ( 2NZEF ) and from new recruits . At the end of November , 146 trainees reported to the Army School at Trentham , where even serving officers and NCOs were required to prove their suitability for positions in the new battalion . Concurrently , recruiting of men to fill the other ranks positions began in early October and within three weeks nearly 900 men had enlisted . The process was carried out by recruiting officers who worked closely with tribal authorities , and the recruits were restricted to single men aged between 21 and 35 , although later married men were allowed to join , but only if they did not have more than two children of similar ages . 
