Can a player move their units to multiple different battlefields simultaneously in a single action?

Ruling: No, moving units to multiple battlefields simultaneously is not legal. The move action allows you to move any number of ready units to one target location.

Nuances:

• It is possible for abilities to move units to other battlefields while one is already being contested, but that combat will wait until the current one is done before immediately starting.
• If multiple showdowns occur, the turn player orders them (open showdowns resolve before combat if it matters).