I’m inclined to advise against it.
You still have to do the insulating and leveling layers in your hearth, which is most of the work involved. The stones obviously aren’t the ceramic ones built for home oven use (which in my experience all crack sooner or later), but if one of them ever failed, you’d be SOL for replacing it because it would be sealed in under the edge of the barrel arch.
The advantage of the brick hearth laid in a herringbone pattern is being able to replace a single brick should it ever be necessary. The only fiddly thing is filling in the points around the edge of the pattern. (And dirty little secret: you just have to do the ones that are an 8th of a brick in area or larger, because the small ones around the edge will be covered by the arch. I’d still do them, but they are only seen along the front edge.)
Hope this helps, Tom!