Two other moves that you can try with UK is: take the fleet from india and attack Kwangtung. This is a risky move but with the fighter supporting the infantry you can kill their infantry and even take the territory. When I do this I’ve noticed that it really slows Japan down. It splits their forces in half in Asia and leaves a carrier and fighter and transport right next to Japan.
Or you can combine your fleet at India with the transport and sub by Australia. This forces japan to attack this fleet which can cost them dearly. OR UK will be able to effectively use those infantry units in the south pacific to reinforce Asia or island hop.