I don't use declared actions. Not even declaring OB/DB split. Combat should be much more fluid, and people can react pretty easily for the most part within a 10 second round.
Imagine how crummy a basketball game would be having to declare actions for 10 seconds, then cancel action because a second player came to defend, in a split second you can choose to dribble a different direction or pass the ball, or even shoot, then get ready for a rebound if you miss, or a number of other things, all happening in a few seconds.
Declaring even OB/DB split isn't realistic to me, so I play it much more freely and open.