says... Accepted answer #1
Since you control both creatures, you will get to choose the order the triggers resolve in.
Things get a bit messy based on when you sacrifice the creatures. If you’re sacrificing them as part of the same effect (i.e. sacrifice two creatures) then all the triggers will happen at once and you could order all four triggers.
If you sacrifice individually (i.e. sacrifice a creature) then the order you sacrifice the creatures in matters. If you sacrifice the Reaper first, it will trigger for itself, but the second creature will not trigger Reaper since it will already be dead. In that case, you would get a Reaper and Artist trigger first, which you would put in an order of your choosing; then the second creature would only give an Artist trigger, which would resolve before the other two triggers as it went on the stack later.
If you sacrifice Reaper second, you’ll order the Artist and Reaper from first creature; then order the Artist and Reaper from Reaper’s death. These two sets have to be in their individual groups, so you can’t do an order of Reaper/Reaper/Artist/Artist
June 15, 2019 1:39 p.m.
@kcom: Since it's pretty clear you got a satisfactory answer to your question, I went ahead and marked it as the accepted answer. Please remember to take care of this yourself in the future, using the green "Mark as Answer" button on the post that best answered your question.