I've lost a sIG 33B because it was in bypass of a multi-hex building that suffered falling rubble from a Russian OBA rocket attack, and B24.121 applied. No chance for a save, just a grave of bricks, dust and broken twisted steel reinforcing rods. If it happens once, you'll learn not to park OT AFVs in bypass of buildings when rubbling is as large of a possibility as it is in a RB CG III.
Good places for mines early are to stop the German advance on F5 and B12 buildings, or to prevent the Chemist's Shop (the printed one, not the real one), from falling too early and intact to a surprise German assault. F5's sewer hole can be the way in and out for your Russians defending the building until it falls, and the Germans MUST take it, by Day 2, or face a huge salient in their rear area along the most important map edge for them to advance. The "standard" German tactic is a smoke barrage and assault via 548/238's. a 6 FP mine field would slow that down tremendously, and moving via sewer into and out of the building would not attract suspicion they are there.
A second good spot is to cover one of the trenches in a 4 trench defense to stop the armored blitz. mines in a single hex building to one side of the trench that allows for exploitation to the riverbank can be a nasty surprise for a German blitz. Frees up some MGs and/or Guns and Mortars for other duties also, on days 1-3.
just some random pennies of thought.
KRL, Jon H