In order for this to work for you, you need to chain your set cards in the correct order.
First off, when Mobius is summoned, and his effect triggers, his effect becomes the very first link on a chain that is activated in response to his summon. Anything placed on that chain is in response to that summon, so cards with the summon response timing (Torrential Tribute, Bottomless Trap Hole, Trap Hole, etc) can be properly activated and placed in this chain.
So you can chain Scapegoat and Torrential Tribute to each other in any order, and Torrential will not miss any timing. With that said, you clearly want tokens on the field after this chain resolves, so you would need to chain Scapegoat first, and Torrential second. The reason why is because the chain resolves backwards. Torrential would resolve first, wiping Mobius and everything else on the field clean. Then Scapegoat would resolve and summon you four tokens (this presuming, you had the spaces available when it was activated)
And as a additional note, Mobius would still resolve. Still destroy Scapegoat and Torrential. Because he doesn't need to stay on the field once his effect is placed on the chain, and Spell/Trap cards remain on the field until the chain fully resolves or their removed somehow. While still doesn't stop the two cards from going through, it's still good to know in.