Composite photograph showing two Sikh men from the same family

This is a photograph of two Sikh soldiers. It is possibly a composite photograph showing two men from the same family. On the left is Sardar Jogindar Singh Nanua (WW2) in the dress uniform of the infantry. On the right is Sardar Batan Singh Nanua (in First World War dress uniform), the note on the back supplies their names and that the older soldier was in "Supply".