I'm still holding out for Sandal being the Maker.
This.....sounds like it may make sense.
Sandal is probably pretending to be "simple minded" as his c=are taker says. Not to mention his care taker even mentions how he just "suddenly vanishes" or "walks around from time to time" so maybe he does certain things "for a reason". Like maybe in DA 2 the reason why Sandal did what he did near the end of arc 1 in the cave where Hawke find s the horn by offing all of those creatures. What if Sandal knew that the creatures were going to ambush Hawkes group while everyone was asleep so he just SMITED them all but made it out like he just threw one of his enchantment stones and that was it. Maybe he does things for a reason without anyone knowing then just plays people for fools.
You may be onto something there.