"Make sure it is hard to avoid most of your Boom Mines. They can deal decent damage to Scorchers." - yeah, please, do so, so that it is easy to deliberately send maxed out scorchers at full boost to take them out. At 80K+ HP they don't care about boom mines.
There is no defensive strategy against maxed out scorcher+heavy+zooka army at full boost or maxed out scank army at full boost apart from two DC 3 and 10 boosted ice.