What makes Silver Peak so tricky is ED-E's Advanced sensors perk seems to turn off and the cave is laid out in a way those Cazadors can circle in behind you. No matter how careful I am 1-2 of those evil things seems to nail me right in the back and I only get the red marks on the compass when they are really close. It's one of the better done "high-risk" caves in the game. Wish they where all like that.
I'm pretty sure that cave, and Vault 34 use a triggered spawn to make enemies appear when you pass a certain point. Same as Black Mountain. Ed-E's perk doesn't work because the creatures that are sneaking up on you don't actually exist until you trigger them to spawn.
A somewhat cheap, but effective tactic. Messes up people who plan out their attacks carefully though.