Unlike the other two cards, Sphinx of the Second Sun provides an entire beginning phase : untap, upkeep, and draw steps
As long as its equipped, you can cast creature spells from the top of your library, and the boost it gives (+2/+2, vigilance, and green mana generation) makes any creature a threat and a ramp engine
Their value is much more a factor of the overall card strength than is normally the case with these kinds of "type of effect" list
Dread Wanderer goes a long way toward making this combo more reliable
Etched foil has been hit or miss ever since it debuted in Commander Legends
This class enchantment is the perfect engine for a spellslinger deck, helping filter away lands (and fuel Underworld Breach) while making your mana better and stretching your Guttersnipe into a win condition