Team cards are the way that team strategies and coordination are best used imo, having civilizations team together to form very strong combinations due to cards should be part of the game imo.
I noticed that Russia duelling school (previously team infantry train 25% faster) was changed to no longer effect team. I understand the logic of not making grenadiers and petards instant for the whole team, but I still think this is a card that should stay as team. I also am aware that this would primarily effect team treaty games (1v1 faster training cards are almost never used, and in team supremacy they come into play but only late game), I think taking this out of team treaty games would also make them somewhat obsolete.