their is no diffenrence between market and index. Index is normally a “market”.
SGX is the broad market index and SGI is a sub-set of SGI and is the 30 biggest stock of SGX index. SGI is still a index.
Market-oriented is a style. It means that it look not for growth stock, not for value stock, but stock that seems interesting and undevalued on the market.
Here you can compare GB1 with both index if it helps you. you can see that it is neither growth or value.
as I am scratching my head. I think I may found your answer. You should compare it with STI since the average market cap of the company are way more in-line with the SGI index than the SGX index. Comparing it to SGX would create a bias since the avg market cap of the companies or way to different.
Also, in the CFAi books, they say : A value oriented portfolio has a very clear bias toward low P/E and low P/B and high dividend yield. p. 213 book 4