Huh. Unexpected styles but all pretty cool. Okay, the shield/stripe emblem is kinda lame but the other 3 are cool.
I'm not sure what I'd use the Kraken ones for other than maybe an "Iron Born" army . . . like a space wolf army themed on the Iron Born from game of thrones, as though the Iron Islands are a place on Fenris.
Skulls are always fashionable.
The eagle pads remind me of Judge Dredd. I could definitely see an army of blue/black marines themed on the judges wearing symmetric pads, one regular and one eagle.