War isnt all about just having a rifle and comparing it to another rifle, they had this and had very limited ammunition:
http://en.wikipedia.org/wiki/M1917_Enfield_rifleNot only that but half their units weren't even armed because there weren't enough of those rifles to go around. Combined that with Japanese air and artillery support plus machineguns and tanks and you can deduce that the Japs didnt have too much trouble. The USAAFFE fought well and delayed their timetable for months but without reinforcements they were lost.
and I would take the Garand over the LE anytime, its capable of accurate, semi auto fire and Patton said it was the weapon that won the war.
Singapore meanwhile, was ready for an attack from the sea but the Japs just went in from behind through the Malay peninsula and took it. Pretty smart move by the Brits to leave their rear unguarded...