The ShiftstonedEternal Power Calculator is a deck-building tool that visualizes your odds of drawing enough Influence and Power based specifically on the cards found in your deck.
This version of the combo just fills the board with Heralds and clears the enemy board with Displays? It's probably better to run maindeck Gleeful Firebrand or market Pyrotech Explosion to end the game when you combo. You could also run Skycrag Stranger over Kato in the market to get the influence for WWH and Pyrotech.
End of Hostilities makes two heralds, you can use one of the two to play End of Hostilities and the second herald to play Display of Destruction to sacrifice the herald and generate 6 power. So you are able to play 2 heralds 10 times and generate a ton of power. Another version of this that I saw previously ended with Reweave to play Iceberg Shineefinder as a finisher. You can also make copies of scattershot for more pings if you manage to draw both copies of End of Hostilities
A single maindeck Gleeful Firebrand would probably be pretty good so that you can reweave for it mid-combo
You often have some junk on the board when you start the combo, so you're not getting the full ping count.
I've played isomorphic's One Turn Faster Than Scavenger a fair amount, and I liked the Firebrand kill there.
With Salvo, you need 7 cards to go off not counting power: 2 Merchants, a 1-drop, and 4 cards to exchange to market.
With Crack, if your merchant doesn't get killed, you need 6 cards to go off, a Merchant, a 1-drop, a 2-drop, and 3 cards to exchange to market.
With Crack, if your merchant does get killed, you need 7 cards to go off, 2 Merchants, a 1-drop, a 2-drop, and 3 cards to exchange to market.
With Crack, you can go off over multiple turns if you don't have enough power, and you can skip playing the second Merchant if the first doesn't get killed.
With Salvo, you can go off over multiple turns only if your first Merchant doesn't get killed (because the Reweave must target a Merchant). Otherwise you need to play a 2-drop and Merchant in the same turn.
With Crack, you need to maindeck 2-drops which leaves less space for 1-drops and Merchants.
With Salvo, you can run more Merchants, but that pushes you into 4 factions.
A single maindeck Gleeful Firebrand would probably be pretty good so that you can reweave for it mid-combo
I've played isomorphic's One Turn Faster Than Scavenger a fair amount, and I liked the Firebrand kill there.
I'm not sure about Blazing Salvo vs Crack the Earth as the 1-cost spell. Just going to list some pros and cons.
With Salvo, you need 7 cards to go off not counting power: 2 Merchants, a 1-drop, and 4 cards to exchange to market.
With Crack, if your merchant doesn't get killed, you need 6 cards to go off, a Merchant, a 1-drop, a 2-drop, and 3 cards to exchange to market.
With Crack, if your merchant does get killed, you need 7 cards to go off, 2 Merchants, a 1-drop, a 2-drop, and 3 cards to exchange to market.
With Crack, you can go off over multiple turns if you don't have enough power, and you can skip playing the second Merchant if the first doesn't get killed.
With Salvo, you can go off over multiple turns only if your first Merchant doesn't get killed (because the Reweave must target a Merchant). Otherwise you need to play a 2-drop and Merchant in the same turn.
With Crack, you need to maindeck 2-drops which leaves less space for 1-drops and Merchants.
With Salvo, you can run more Merchants, but that pushes you into 4 factions.