Let me clarify a bit. A Shaman generally face tanks mobs because of the summon mechanic. You can't root rot them, which is another common Shaman strategy. But there are not a lot of mobs in the game that summon AND are face tank-able without slow. This means in general you are face tanking slow-able mobs, and that means they are much less likely to interrupt you via melee anyway.
However, some mobs can be tanked by the Shaman pet.
https://www.youtube.com/watch?v=umuVBewCNgY This video shows me killing a Cliff Golem by having the doggo tank it instead. Doesn't work on WW dragons sadly, they hit too hard, but you can still do this with some summoning mobs.