Diversity AW - Signaling
The game could signal, in the formation of the team for the war, if that hero is already inserted in the map, in the same way that signals the synergies.
This would help to diversify the maps and the alliances to gain more points would be important. Also, whoever leaves to position team later, would have more difficulties to put unique heroes.
I think it would be a good update, I would suggest and put into discussion.