Following majority rule in early 1980, British Army trainers oversaw the integration of guerrilla fighters into a battalion structure overlaid on the existing Rhodesian armed forces. For the first year, a system was followed where the top-performing candidate became battalion commander. If he or she was from ZANLA, then his or her second-in-command was the top-performing ZIPRA candidate, and vice versa. This ensured a balance between the two movements in the command structure. From early 1981, this system was abandoned in favour of political appointments, and ZANLA and ZANU fighters consequently quickly formed the majority of battalion commanders in the ZNA.