I ran the test again with the Russian infantry on Hide in the houses, but this time I gave them very short 10m arcs to see what would happen.
The Germans advanced as before and spotted the squad in the house on the left at about 30m and began firing at it, forcing it to flee out the back door after less than a minutes firing! The squad had only suffered one casualty so I'm surprised they legged it so soon, but I think they were out of command (white arrow) to their platoon HQ which might have made them crack..
I then ordered the Germans to move into the other house, and amazingly they still hadn't spotted the Russians even though they'd closed to about 10m. Here the Russians fire first and blow away the point man as he enters the 10m arc..
And a pointblank firefight erupts, some Germans ran in the front door and were cut down, and others got it among the brussel sprouts..
But the Russians quickly call it a day and flee out the back door despite only suffering 2 casualties. They were out of command to their platoon HQ like the other squad which may explain their shakiness.
Conclusion- Houses give excellent concealment to units on Hide who are not firing, as they won't usually be spotted until the enemy gets to within about 30m or less.
PS- is there any way to make infantry advance in realistic line abreast? In all the tests above the Germans advanced in columns and I couldn't make them spread out.
I also need to brush up on command links, for example the squads in the houses had links to their Company HQ, but not to their Platoon HQ and Battallion HQ, must they have links to all 3 to be in command?
Incidentally all the tests were conducted on a clear sunny day with a random mix of units with various Experience/Motivation/Fitness and Leadership ratings, so in actual combat spotting might be better or worse depending on weather, night, troop quality, tiredness etc.
I also used the 'Warrior' difficulty level because it's the middle one of the 5 levels and gives a good balance of realism and playability.