As Slim went about training his men for the rigours of jungle warfare, he clashed with Brigadier Orde Wingate, who took away some of Slim's best Gurkha, British and African units for his Chindit raiding group. Slim argued against the loss of his better units to Wingate, and maintained that though Wingate had a successful career in Palestine and Ethiopia he would discover that the Japanese were a considerably tougher foe than the Palestinians and the Italians that Wingate had hitherto been fighting. However, Slim did approve of Wingate's plans for aid to the hill tribes of Burma. The various hill peoples of Burma such as the Kachins, Karens, Chin, Nagas and the Shan collectively amounted to about 7 million of Burma's 17 million people, and unlike the Bamars, who had welcomed the Japanese as liberators, had stayed loyal to the British when the Japanese invaded. The hill peoples of Burma had suffered under Japanese rule, and were more than willing to wage guerrilla warfare against them. Slim approved of the plans of the SOE and OSS to provide arms and training to the hill tribes as a way to tie down Japanese forces that would otherwise be deployed against him.