The problem with
spider spawning is they get 6 uses of it to your 2 uses of
anger of the gods. Few good players will commit both of their uses of a
spider spawning if they know their opponent is playing red ( for anger of the gods) or white ( for planar cleansing).
Yeah, so you should try and win the same turn you cast Anger. By that time you should have some of their fatties on your side. Anger clears their weenie blockers.
Act of Treason their remaining fatty, if any (should be possible with all the red mana sources) and swing for lethal. The right strategy for Golgari Spiders against this deck is never cast any fatties and win with the spiders only, but I have yet to see an opponent who does it.
Plus
Anger of the Gods is at odds with most of your creatures.
True, but if you play this deck, you'll see that this is not a big deal. First of all, there are only two of the Angers in the deck; if you draw one by the time you have a great board position with Talrand and drakes, just don't cast it -- and this is not specific to this deck; you'll have to make this kind of decision with sweepers in many decks. However, this deck normally wins with the opponents' fatties, who survive the Anger. Your tokens are chump blockers and
Switcheroo trade material, so you don't care; just don't play out all of them if you see an Anger coming. Talrand should be held and played after the Anger. If your Mentor has been on the board for a few turns by the time you cast Anger, it usually has already paid for itself in terms of card advantage.
I wonder if you would be better suited to hold a couple
negates or
dissolves in their place?
Unfortunately no, because Negates and Dissolves don't kill goblins.