How does the declare attackers step work?
As the declare attackers step begins, the active team declares attackers. If a creature is unable to attack one of the defending players, that creature cant attack the defending team. The active team has one combined attack, and that set of attacking creatures must be legal as a whole. Example: One player in a Two-Headed Giant game controls Teferis Moat, which says As Teferis Moat comes into play, choose a color. / Creatures of the chosen color without flying cant attack you. Creatures of the chosen color without flying cant attack that players team.
