I got the Torc Strand of Lore at King's Rest, not Forsaken Heart Cave. I got the Torc Strand of Power from Dire Brambepatch, not Druitularg's Ritual. Similarly for the Torc Tonal Focus, I got it at Buron rather than Wrathvenom. It seems these three (and others like them) are probably any WB in the zone or PD.
The Torc Throat Guards is any Anka'Ra Group Boss, as mentioned (FWIW, 4 of these are grouped around the Sandy Path wayshrine in Lower Craglorn).
There may or may not be a problem with the Torc Strand of Song dropping (Captain Blackheart in Blackheart Haven Dungeon). I haven't got to this one yet but I've seen complaints. Maybe it was fixed in Wednesday's patch.
Given that three of the five leads are not actually restricted to a specific overland WB as stated, this is probably also true for the other Mythic Items leads.
PS: has anyone done a guide specifically on how to tackle Master level excavations? There are so many layers it seems more a matter of spamming heavy shovel and getting lucky than anything else.
Edited by TheRealPotoroo on 8 June 2020 01:15
PC NA, PC EU
"Instead of taking the best of the dolmens (predictable rotation), the best of the geysers (scalability based on number of players), and the best of the dragons (map location and health indicators) and adding them together to make a fun and dynamic world event scenario, they gave us....... harrowstorms." https://forums.elderscrollsonline.com/en/discussion/comment/6850523/#Comment_6850523