It will depend on your list. I play a drop pod list, which is extremely fun and rewarding, by the way, and the core of it is three tactical squads. With that in mind I'm going straight for UM tactical doctrine.
You see, that doctrine isn't quite how you described it. It actually makes ALL weapons in tactical squads twin-linked and every other unit gets to re-roll 1s when shooting. That's why I think that trait is the winner in this new book.
The bad news is that the latest update from
40K Radio claims that Bolter Drill does not affect special ammo, which is disappointing if true. But if you wanted to use Imperial Fists doctrine and use lots of Sternguard you could use a Pedro count-as model. He can make Sternguard scoring.
The Salamander trait could also work well. Pods are obviously in range to cause havoc with template weapons, especially now we can use the 6" disembarkation move. When it comes to Sternguard, you can load them with combi-weapons and give them a heavy flamer for tons of re-rolls. Just bear in mind that though Sternguard are getting cheaper combi-weapons are getting more expensive.
Here's a detailed list of Chapter traits (first spoiler-tagged part):
http://www.dakkadakka.com/dakkaforum/posts/list/543907.page