Although you have to lose the dork to kill a thing unlike Viridian Shaman you are not constrained by keeping it back until needed and are therefore able to curve out nicely with it
Early on, you get a 1/1 flyer for two CMC, which is basically on curve for early sets, with the exceptions of Flying Men and Scryb Sprites, so it can come in early and hopefully do a little damage before eating a Bolt
As much as I like Vivien's Arkbow, it has never broken out as a competitive card
If the squids triggered upon leaving the battlefield instead of at death, Id say that it might compete with True-Name Nemesis in Legacy
Since Strong Back is not a legendary artifact or land, once it's gone it's near impossible to bring back outside of a few cards
If youre interested in the actual artistry behind this card art, illustrator Steven Belledin wrote an excellent blog post about his process