You have 2 cards left in your deck. Playing sin prodder will not change the odds of you top decking that card, which is still 50/50 because neither player knows which card of the 2 is the one you need. Yes after the fact you will know if prodder would have won the game because he cleared the crap off the top, but it does not change the fact that you have a 50/50 shot.
This is the example people needed to understand that Prodder does not allow your opponent to manipulate your draws or affect your hand. I was going to try to get the point across but you've done so elegantly.
The primary purpose of the Shamans is Wasteland resistance, but their incidental value in fighting Crucible, Snapcaster, Will, and JVP is not zero. It's not normally a card I'm a big fan of in Vintage (I generally think of it as "too fair") but it's been very useful in covering the third or fourth color.
I'm just not sure the fifth color is worth adding more fragility to the manabase; especially in a relatively fair list. I'm usually the first to climb aboard the Greed Train but in this case I'm happy to trade it for fewer games of getting randomly crushed by Shops, Landstill, or BUG Fish.
I know, but I'd love if this card could count as a counter for counters on your graveyard... Maybe that would be too busted... Leaving 3 mana open would discourage opponents from playing Recall, Dig, etc, without double backup.
@MaximumCDawg (quick aside, the old site is going to get put back up at archive.themanadrain.com, but there were some technical troubles I haven't resolved yet - the old data should all be there when I fix things though)
There are other options, but it turns out that most of them are good only in really specific situations where in most situations Griselbrand is quite good. I agree on the multiples thing, if I were playing control oath right now i would split 1 griselbrand w/ 1-2 Rune Scarred Demon. I am not, because in this deck, just ignoring containment priest, oathing twice and winning with a memory's journey return'd yawgmoth's will has been real good.
Post board against shops I think your best bet creature wise is a mix of blazing archon (or elesh norn) and griseldad. Blazing Archon literally turns off their chances of winning against most modern shops lists, and griselbrand helps you win the game before they get a trike with enough counters to kill either the archon or you. Elesh Norn has been good, but sometimes you need to oath against, and it doesn't win through Wurmcoil which is frustrating.
I thought Alchemy was the most direct comparison, but if we're just talking about 2U card advantage spells in general, we have to acknowledge that Thirst for Knowledge is probably just better the vast majority of the time.