When playing Arise, what is the correct order of operations for using Weaponmaster and readying up to two units?

When playing Arise!, the correct order of operations is as follows:

1. Playing the Spell

You play Arise! as a spell. Once its costs are paid, it is placed on the chain as a pending item.

2. Resolution of Arise!

When the spell resolves, its instructions are executed from top to bottom (Rule 157.1):

1. Token Creation: You play a 2 [M] Sand Soldier unit token for each Equipment you control.
   • Per Rule 157.3.a, you must finish resolving all effects of the spell (Arise!) before addressing any chain items (like triggers) it created. Therefore, the tokens enter play, but the spell continues to the next instruction before the triggers resolve.
2. Readying: You are instructed to "Ready up to two of them" (the Sand Soldiers created by the spell).

3. Chain Resolution

After Arise! has finished resolving its instructions in their entirety, the chain items that were generated during its resolution are processed (Rule 157.3.a).

• Weaponmaster: If the created tokens have triggered abilities that trigger upon their entry, those triggers are now placed on the chain and resolve in the order they were added.
• Readying: The instruction to ready the tokens happened as part of the spell's resolution, so those tokens are marked as ready immediately upon that instruction's execution.

Summary of Interaction with Weaponmaster

Weaponmaster is a "When you play me" triggered ability (Rule 821.1). According to Rule 157.3.a, you cannot resolve these triggers while Arise! is still resolving. Once Arise! finishes its entire text (creating tokens and readying them), you then proceed to resolve the pending triggers on the chain.

Note: I could not fully verify this ruling against the retrieved rules.