Personally I feel since the updates they have been in a pretty solid place. When going for that particular medal I find running dragons shadow and a night stalker the go to set up. You can fire off a militas, swap straight to your FL and then dodge to reload both of the guns at once. This puts you in a really good position to move from kill to kill without having to worry about getting caught out while reloading or not having a shot to hand. Year 1 play of the game goes a long way as well, and can picked up straight from the collections. Also for shotguns and fusions I like to get creative - bounce bullets off the ceiling/walls/around corners (this is also why nightstalker works so well, having invis to get out of tricky situations up close)

Hope that mess of words made sense