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In 1914 most of the professional Regular Army Battalions were brought back to UK for the Western Front and others.  They were replaced by the Territorials.  This site will tell you which ones were where

https://www.longlongtrail.co.uk/army/regiments-and-corps/the-british-infantry-regiments-of-1914-1918/

The Territorials were of an adequate standard for Garrison duties and many remained in India for the whole war.

The cap badge is a match for the Royal Welch Fusiliers.  It is obscured but probably that one.

The AOS strip is likely to be plain red for infantry.

Dorothy

The concise answer is that they were 2 separate battalions but he could have been in both as men were often transferred to make up numbers.

Alan

The Kings Own Regiment  was probably this one: https://www.britisharmedforces.org/i_regiments/kingKLan_index.htm

It was later linked to Lancaster but at your time period recruitment was not always so geographically linked especially fro Irish men who made up the ranks in many 'English' regiments.

However other regiments such as the 3rd Kings Own Hussars did exist.

The shoulder patch would date the photo to 1916-19 as the were not worn before then so if he was not in the 2nd bn then and you are correct about only them wearing it, then it is not him.  The recruiter badge was a peacetime thing worn on red tunics so the flags are signallers as suggested.