With the existence of both Big Score and Windfall in the Standard meta alongside Goldspan Dragon and Galvanic Iteration, you can expect players will attempt to make an Izzet combo deck
Avenger of Zendikar is far weaker in this role as you have few lands early when it is best to cheat big things in, the plants don't fly nor can you pump them up to being relevant without the Avenger itself in play.Basically, if you want lots of things, if you don't want to die to attacks, play this
For just three mana, one of each of the Bant colors, Morska comes down quickly, potentially as early as your second turn, and at the top of each of your turns you investigate, giving you a Clue token which you can use to draw a card in exchange for two mana
Finally, Sandstorm Verge reads like basically an unplayable card that I would only be interested in if I get lucky and end in a mono colored aggro deck