Can the tokens I play from Vanguard Armory be instantly placed at a battlefield?

No, you cannot play the Recruit tokens from Vanguard Armory directly to an open battlefield.

According to the official ruling for Vanguard Armory:

• Tokens must be played to valid locations: A valid location is your Base or a Battlefield you already control.
• Open battlefields are not valid: An open battlefield is not a valid location because you do not control it yet.
• Standard rules apply: While Vanguard Armory allows you to distribute the three tokens across multiple valid locations (e.g., one to your Base and two to a controlled Battlefield), it does not bypass the standard rules for where units can be played.

In summary, you must control the battlefield before you can play a token there.