As a silver-bordered card, Grimlock is not legal in officially-sanctioned events and formats but is fine for casual play, and as such gets a bit silly with its rules
As such, while missing out on a Street Wraith or Cursecatcher might be frustrating, by the numbers, the odds of this happening are fairly high
Snow Villiers While lacking some of the downside of some similar creatures, you also have a capped upside on a middling cost creature without evasion who can be rendered impotent by destruction of other things
Hazoret, Godseeker is a little different though, as you need to jump through more hoops to attack with it
Once you cast a spell using flashback, that spell will be exiled once it leaves the stack, whether it resolves, is countered, or tries to resolve but fails
If someone lets you get to that point, theyre probably not packing a lot of removal, but hey, its powerful