Is there a trick to killing the super and heavy soldiers?

[Coldhands]

I beat the game on Uber already, but I my basic strategy for super and heavy troops was just shooting them a whole bunch from cover. If I could get to a turret, or had rockets, they were toast, but when I didn't it felt like I was just taking the brute force approach and maybe there was a better way.
Do they have weak spots I should have tried to snipe or something?

[The_Squarecrow]

Laserkraftwerk charged shot in the face.

[Jack Greedy]

Shoot the two glowing glass "transistors" (these yellow things) on their back.