I think the one in the middle is Royal Artillery and the other two could be either 10th Royal Hussars or The Welsh Regiment. Need a close up scan of the badges to really see the difference.
Salty
Actually there are about 4-5 different Regts those x2 could belong to!!!

But yes the scan would be great!!
As for ther first pic...
India pattern helmet better known as a "Cawnpore"
One set short puttees, the rest are Web Anklets (gaiters)
All in KD, 37 ptn Web Belts, but not "Bombay Bloomers"
The Cawnpores have a two colour diamond...I good dig is required on this one!
The CSM (?SSM) is the highest rank...the rest are Cpls and Ptes...Not Sgts or officers...
??1943-4 due to the style of KD shirt...