Hey Andrew
You have made a good start to these figures mate. The weapon slings look the part.
A few suggestions?
The are begging for a wash to bring out the creases and details more!
Add a black wash to the metallic parts of the weapons.
Check and see if any of the figures are wearing gloves? A couple of hands look mighty 'chubby' and lacking in definition...
Paint the buttons on the coats. I think they were initially brass, but then were made from plastic and coloured OD, which would be a more brownish version.
The overshoes they are all wearing should be black, with bare metal straps/buckles.
I think some little things like these will make them stand out from a crowd. For added 'uniqueness', why not have the kneeling rifleman hold the sling through his left hand to take up the slack?
These potentially can be a nice set, but for the softness of the details and that NCO who looks far too rigid! I'd probably rate their quality as per your first photo, from left to right