Depending on location and training all those new AAA batteries , even with High Explosive or AA rounds can make swiss cheese of Japanese tanks if used like the German 88mms.Historically the 12th Indian Brigade was, in my opinion, on par with the Australians, and may have been even better. They had been fighting for the best part of a month, mostly as the rear-guard of the retreating III Indian Corps. Owing to the failure in command of 11th Indian Division, Murray-Lyon had been replaced by the CO of 12th Brigade, by Brig Paris, with the CO of the Argylls, Lt Col Stewart stepped into Paris's shoes. A very tired Stewart, new to commanding a Bde, made mistakes in deployments and was badly punished by the Japanese. In fairness to Stewart, at that time, the British Indian forces were in desperate need of time to rest and regroup, but Yamashita kept the pressure on, and they cracked!
Currently (January 1941) neither historically or in my timeline, there are no British tanks or talk of any being sent. And air cover in both timelines is pretty much non existent.