Soviet doctrinal placements of units are in a flower pattern, with sensors/logistics units at the center and launchers arranged an a circle around them spaced no more than a few hundred feet apart. However, this is a very easy arrangement to spot from the air, so guerrilla forces throughout history have been known to use other arrangements for the sake of concealment. Since reuse of sites is a common practice, these rules are frequently applied to newer SAM batteries, as well.
One of the easier systems to evade, the tracking radar is easily fooled via notching and chaff bursts of at minimum 4 per second. Chaff on its own is 3× more likely than normal to spoof the V-755. Missiles have no guidance of their own: defeat the track radar to defeat the missile. Missiles guidance is fairly stupid, and can be dragged into the ground. It is also completely unable to track targets at sub 300 ft altitudes, leaving it vulnerable to low runs. As a result, sites should also include short range anti-air able to engage at low altitudes, such as AAA guns and MANPADS.
But more than that, Eagle Dynamics have in their infinite wisdom decided that the weapon system that forced an entire new air war doctrine and mission tasking, with specialised aircraft, weapon systems, defensive systems, and specialist schools to be developed to combat it, is pretty much just a pop gun. Due to the SA-2 in DCS only using pure pursuit rather than any kind of proportional or otherwise predictive navigation, it can be defeated by flying straight and level at above 300kts, making it a threat to A-10s, a few helicopters, and not much else, and those can generally quite easily fly below its engagement altitude. Any kind of fighter aircraft or jet bomber or even most transports are completely untouchable by this weapon system.