When a Merchant moves to a Battlefield with an enemy unit, does combat start before or after the Merchant's movement trigger resolves?

Ruling: Combat does not start until after the movement trigger resolves. The Battlefield is marked as contested, but combat (showdown) is staged until the chain is empty.

Sequence:

• Merchant moves to Battlefield with enemy unit
• Movement trigger goes on the chain
• Battlefield is marked as contested
• Trigger resolves
• Chain empties
• Combat/showdown begins

Nuances:

• If all attackers and/or all defenders are removed before the trigger resolves, there would be no combat since combat hasn't started yet