As far as I can tell, it's not. Not only it's not like that in the sky (the constellations are not in this position), the myths associated to them are different. Sagittarius is the Centaur Chiron, the scorpion is the one that bit Orion. read more
Scorpio and Sagittarius are mortal enemies though the closely share the same strength and traits, they shall both fight for dominant occupancy. Genesis 49:22 "Joseph is a fruitful bough, A fruitful bough by a well; His branches run over the wall. 23 The ARCHERS have bitterly grieved him, Shot at him and hated him. read more
Another Greek Sagittarius Mythology tale tells of how, Sagittarius the Archer was directed to shoot down Scorpio the Scorpion, while Scorpio had been sent off to murder Orion. This story gives the reason why the Archer's arrow is aimed toward the ‘heart of the scorpion’. read more