Can a player switch which champion unit they have starting next to their legend between games in a match?

Ruling: Yes, players can switch which champion unit starts next to their legend between games in a match. The chosen champion can be swapped between games according to tournament rules.

Nuances:

• An earlier statement suggested this was not intended and that the Champion Unit is a set part of the deck like the legend, but this was superseded by updated tournament rules when the game launched.