Can you play Champion units (outside of the Champion Zone, just normally in your deck) in decks where the legend doesn't have the same champion tag?

Ruling: Yes, you can play Champion units in your deck even if they don't share the same champion tag as your Champion Legend, as long as they conform to normal domain identity rules.

Nuances:

• Your Chosen Champion (the one in the Champion Zone) must have the same champion tag as your Champion Legend
• Champion units played normally in the deck are not subject to this same-champion-tag restriction
• Currently there are no Champion units with multiple champion tags or other unusual tag configurations