PXL_20210124_205206994

It would be interesting to see the rest of his Service Record such as where he began his service. I have difficulty reading much of it and am not very quick at typing. It remains to be seen if he joined a Front Line TA Regiment or Second Line Home Service/ Training Unit.
There were frequently too many recruits and not enough weapons so they created Front LIne Regiments to go to War abroad and Second Line Home Service Regiments
In general he seems to have gone as you say to Sierra Leone to the Gold Coast then India. This is not unusual as West African Troops were trained in these areas on Artillery equipment then posted to India to fight the Japanese in Assam and Burma.
I have instances when a lad joined his local TA Regiment but was found to be too young to serve abroad. His mates were sent in 1939/40 to load Anti Aircraft Guns in Bristol but he was held back with the second line Regiment for Home Service training. He was injured in an accident and medically downgraded to stay in the UK. After training he passed all his tests to become a Sergeant on the guns and was eventually posted to West Africa to train gunners there as it was in a non combat area. The African Gunners went to India where they were posted to the front in Burma.
A bit of a long winded story and not a direct transcription of the records but might hopefully give a more capable admin person a few ideas as to the background behind these type of moves.