Before I came back to the game last year and became the WAAC player that I am now, I used to buy models just because I like them rather than because they were good on the field of battle. Now I absolutely love the new Legion of the Damned models but Space Wolves don't need help from any warp dwellers (well, apart from the 13th Company obviously). Okay, so I could get some to use in Apocalypse or just use them in friendly games (in the grim darkness of the future there is only paintball). Fortunately, Kill Team gives me the perfect excuse to get a squad.
So, let's look at the basics - Deep Strike with potential to re-roll scatter dice. Invulnerable 3+ save. Slow and Purposeful (move and fire heavy weapons and assault after firing Bolters, count me in). 2 attacks base. However, they are 155 points for 5 men. For that I can get 10 Grey Hunters with 2 Meltaguns. It's also 30 points per addition Marine - very pricey. The special and heavy weapons are also very expensive so we're struggling to get much in at 200 points. How about:
Sergeant, Bolt Pistol, Chainsword
4 Legionaries, Bolter
Legionnaire, Heavy Bolter
That comes in at 195. The sergeant swaps his Bolter for a Chainsword to give him an extra attack and we have one guy with a Heavy Bolter to make the most of moving and firing. The Heavy Bolter is the cheapest heavy weapon and 3 strength shots should kill most basic troopers.
Optimal? Maybe for LotD but they're pretty sub-optimal to start with. Hard to kill? Not especially, even with 3++ they'll get torrented to death. Hard to beat? Nope, lose three guys and you start taking those leadership tests. But those models are so good...