USMC Long-range Fires unmanned ROGUE-Fires JLTV chassis with Mark 41 launch cell for Tomahawk missile. The US Army is said to be interested in acquiring this as well.
https://www.twz.com/land/usmcs-tomahawk-cruise-missile-launching-drone-truck-eyed-by-army
While SM-6 works for a number of “large” targets, is there something similar for the smaller drone/drone swarms that more cost effective per shot?
Not for the Mark 41 VLS cell. There is the Evolved Sea Sparrow Missile (ESSM) that can fit four in one cell, but that doesn’t mean that the ESSMs are cheap either.