It was never a two-sided war to begin with before 1947. There are skirmishes between both migrant Jews and Arabs, but the Irgun, Lehi and Palmach got the extreme upper hand because they had far more weapons cache, and that was because of their objective in defeating the entire British army and police who were defending the British Mandate and the Arabs. Refer to my previous post:
Post in thread 'Middle East Conflict'
https://forums.bluemoon-mcfc.co.uk/threads/middle-east-conflict.334241/post-17595385
There is a detailed account of how the pre-IDF in the 1930s and pre WWII, against the knowledge of the British Palestine no less, imported to Palestine thousands of weapons munitions and armaments from Germany. They imported hidden from the ships several times, and only on 1 occasion did the British officers expose a hidden ship container that were supposedly food and spices, which then led to the officers rushing to the Mandate HQ to inform their boss of what they found, but instead killed by the Irgun et al militia/terrorist.
And after WWII they imported illegal arms via Czechoslovakia, more arms and munitions provided by the Sonnebon group; the Jewish-American group who were for the mass displacement of Palestine.
The only Palestinians who had weapons and munitions were citizens with WWI era weapons and the 4000 Palestinian police and soldiers who were legally employed by the British Police and Army for British Mandate of Palestine.