Cool stuff - though there are a few areas that need revision.
For one, I have already drawn a pretty accurate and correctly-scaled version of Rhodesian camo for North Point:
This was created by roughly tracing several photos of shirts and jackets after resizing them into the correct scale. I also created some of the pattern using my real Rhodesian camouflage jacket and some measurements.. (I went to that extent to get an accurate pattern... :/)
Second, the webbing and personal equipment is wrong... you have shown the field-equipped soldiers wearing Pattern 58 and some sort of four-pocket belt which I assume is an attempt at creating the unique chest rig worn by Rhodesian soldiers:
Here is a version I've drawn (also for North Point, but using my own example as a reference):
The Rhodesian webbing was a mixture of Pattern 58, South African Pattern 61/64, and occasionally SADF Pattern 70... really whatever they could get their hands on. For an ORBAT picture, though, it would be best to draw the Rhodesian webbing itself. The Varusteleka gentlemen do a good job of reproducing the "look":
http://www.varusteleka.com/pictures/13922e.jpg
Here's a highres photo of the webbing itself:
http://www.freewebs.com/dudleywall/Webb ... 0front.JPG
Last comment involves the plimsolls / canvas basketball shoes worn by the guy with the shorts... they aren't correct either. The most commonly seen shoe is the black Converse:
https://warosu.org/data/fa/img/0081/84/ ... 749059.jpg
I would also camouflage those rifles if you are portraying a post-1975 RLI.
Otherwise, looks great - I really like the dress uniforms. Now you can work on your next project: portraying this guy, whoever he is!