A significant portion of the heat in an IC package is conducted away from the IC through it's bond pads to the connected pins to the board/copper traces/power and ground planes. Increase the copper on the board (like Gigabyte did a while back) and lower the IC temps. Add thermal pads and a big honking heatsink on the backside and lower temps.
I see. Wouldn't having a much larger area of contact on the chip's surface be better than getting it from the pins? ie. I've seen a few thermal images of GPUs and the whole chip is highlighted in red no just the pins.
I have their air-only cooler on my R9 290X, and it also leaves the VRMs without any additional cooling. There is however a way to deal with this: take the original heatsink and a metal saw. That lowered my VRM temps to ~70 on load. I'm not sure about the "they can take a lot more" comment, do you have the specs for the ICs?
The cooler directs air downwards towards the chips though albeit a bit warm from the heatsink. With this setup there's no air being blown on them at all.