After many many attempts and an awful lot of learning by doing (no real life military experience), I am proud to say that I have finally completed the first scenario 'An August Morning'...
It wasn't easy and I wish I had the time to write an AAR but the mission was so intense and I was so concentrated that I completely lost myself in the mission and forgot to take any screenshots.
Thanks to the information shared here and, after watching a few playthroughs on YouTube, I figured out a plan and positioned my MGs carefully so that they could provide cover while I sent in a split team of infantry to collect the documents. An earlier mistake had seen me trying to 'Rambo' my way through the scenario under the impression that I had to kill everyone to win.. and then the realisation that this was based on real world strategy and that the AI was smarter than I had expected and that my mission was only to get in, get the job done and get out alive...
Regarding military tactics and protocol, I feel like I am drinking from a fire hose but I cannot wait for the next scenario..
A huge thank you to the scenario author and the developers for such a marvellous military simulator.