Yeah I feel like the battalion is super necessary, annoying it costs so much though =/ 180 points is literally another unit of fellwater/rockgut. But the option to have an artefact on your boss and the hag is just a little too good not to pass up, plus you can make a realistic 4 drop army giving you some choice about who goes first.
I do like the idea of the Glowy Howzit on a Hag but that 1 roll to break it is a little offputtinng. A flat -1 to hit for the entire game to me feels better, at least more consistent, as an option. If you can identify a key target and get her engaged with them, being -3 to hit is going to make most units literally unable to get damage in. Factor in the shade spell from Madcap shamn and she can be -3 to melee and ranged, which is just great.
Troggboss artefact wise i'm still unsure what the best options are. Seems like it's a direct competition between Rageblade + Pulverising grip for a great chance at insta-removing 2 models from a unit per turn or going for artefacts/traits that buff his already strong hammer. Guess it depends what you're expecting to face? Again, erring on the side of consistancy RageGrip build is an almost guaranteed model removal tool against almost any battleline unit. Taking 2 sequitors out of a unit before even hitting them is a lovely idea... (not to mention if you have a Dankhold and a gargant as well, that's a potential 4 model removal per-round)