idk about nm or hell. but for norm i haven't had an issuee so far with totemnec up to mephy. . . . . just 1 fireheart, and 2 frostclaws's. summon totem, teleport them all in front, and walk backwards. totems do all the work . . . . . i abuse the fact that they have a healthpool early on to do most the tanking for me so far.
edit: keeping frostclaw maxed seems to be what does this though, that one totem massacre's bosses. . . . alongside life on kill, i can just run up through several mobs, summon 1 totem and teleport to it. it waveclears everything for me
as for pesti, if it could be used during Deathlord (cast inside not cast then deathlord) i could see it having some viability as a farming build for speedclear content. i figured even without it may be decent for clearing. as necro seems to be relatively slow reaching bosses to kill. that summon totem > blink, and needing pax mystica to tele over walls seems to be somewhat problematic on traversing stuff quickly without the 3 second teleport charm that doesn't rely on totem and can go through a wall.
It's the reason i considered pesti or rotting flesh . . . . they can screenclear without needing 2-3 buttons and then time for the spell effects to go off from totems, or summons to reach the target. Which when farming your first TU set, can be a pretty big thing since you're repeat killing the same boss numerous times.