Can you use Recruit the Vanguard from a different battleground to summon recruits onto Grand Plaza during a showdown at that other battleground?

Ruling: Yes, you can use Recruit the Vanguard from a different battleground to summon recruits onto Grand Plaza during a showdown at another battleground. Action cards played during a showdown are not restricted to the battlefield where the showdown is happening.

Nuances:

• Cards played from Hidden are restricted to the battlefield where the showdown is happening
• Action cards do not have this restriction