Now that MM Sniper is trash the only way you can get bursty ranged DPS is Arsenal Merc, that's probably why there is an increase. Also I myself have relatively recently learned how amazing smash Jug is in 4.0, trying it after seeing all the posts on the forums and hearing friends say how good it was. I liked the Mara version but figured Jug wouldn't be all that much better, after all you get some neat cc immunity on Mara, but I was very pleasantly surprised.