Why is Auriok Salvagers a Rare in Modern Masters, yet this is an Uncommon?

Imho, when they were to give one white Uncommon from Mirrodin a Rarity boost in that set, they should have gone with Stir The Pride instead.
This card has great potential in any creature-heavy deck and is especially nice in casual.
I remember some of my earlier games against my cousin's altered Swarm and Slam deck, and i lost more than once against him, thanks to that card - and when that happened, he usually ended up with 50 or more life.

This would have been a nice casual Timmy rare, and would have certainly made more people happy than those getting Auriok Salvagers in their rare slot - while at the same time neither of them would have gotten any notable value change.

Then again, Auriok Salvagers might got the rare slot instead so that he wouldn't show up as many times as this card.