An accomplished player will learn to read each others powers, and pose accordingly. Combat isn't a matter of picking and choosing to which attacks to respond. You react to everything that is relevant. And you react exactly according to what was posed.

Slow down when posing, don't rush and leave others behind. When combat gets intense, allow one action per turn. Net lag is our constant companion, some people may be trying to catch up. Try and adhere to a system of one pose each at a time, and be realistic about the contents of the pose. Loading a gun and firing it should generally be two separate poses. Allow the other person time to react, or the purpose of the battle is defeated. Especially in larger battles with multiple participants, the spam tends to slow people down. Not everyone may type as quickly as others.