I don't think all of them are there all the time besides the ones already mentioned. I don't think the one in the far NE corner of the Ancient Temple was there the first time I looked (the room with the 2 gold statues). The one in the 2nd small lake in the Rocky Path wasn't there when I looked for it, but I found one in a waterfall not far from the Eastern Lands Entrance to the path. I have 8 so far, and now I have a few more leads as to where to look. BTW, I'm playing Normal Mode.
I only saw 2 in the church that the ghost takes you to. I went in and out many times and still there were only 2. BUT I somehow managed to get the one listed at #1 on the list BEFORE I got the myst bag (my mouse showed the magnifying glass and I checked it - I didn't see the butterfly, but got it anyway)and then got it again AFTER I got the myst bag (this time I saw it). That will make a total of 12 for me (still have rogue territory and sapphire cave ones to get).