regnak: OK, I have tried 3 or 4 times to get a piece of the evil totem pole. Each time I send the 4 required Valets and each time I fail & they die. Will it help to send extra Valets or will they just die too?
Always send more minions than you need - that way if some die, as long as you still have > than the required number, you'll still complete the mission (and get the part).
Also, I'd always try to send other minion types as well: military minions protect other minions (so less of them die); social minions reduce heat buildup (so you have more time before an enemy agent shows up - which tends to kill more minions on top of what the mission takes out); science minions (I think - from memory) reduce mission time taken, so you're more likely to get out of there before suffering too many losses.