Let's put the lineout issue to bed.
There are too many options these days for a lineout caller to have the final (or even the major) say in which play to adopt in most circumstances.
Will the throw be to the front, the middle or the back, or even over the back? Will the jumper being moving backwards or forwards or standing still at the target point? Will the catcher tip the ball back to the half (or acting half) or to the hooker running around the back? Or will he catch it in both hands and than pass or bring it to ground? Will the catcher immediately be brought to ground or will he be held in the air for a second or two to try to win a penalty? If he brings the ball to ground, will a maul be formed or will he pass to a prop or hooker running around from the back? If he tips to the acting half or passes to the acting half, will it lead to a maul initiated by the acting half or will it be passed to the backline for play? If the catcher tips or passes to the hooker running around the back, will it then lead to a maul or will he act as distributor to the backline or just form a pod with other forwards and attack the gain line? If it is a throw to the front of the lineout, will it go back to the hooker for a run down the line? If the ball (on rare occasions) goes to the backline, will there be a hit up in the 12 channel or will it go wide?
There are simply too many options and decisions to be made to have it all contained within a code as called by the lineout caller. These are strategic type decisions that seem to me are sorted out in a collegiate fashion in the forwards get together before each lineout. The call on the play to be adopted must be made by team leaders, and in the case of the Wallabies, I would say those players are Coleman and Pocock, not the so called lineout general. Once the play has been decided, the prop simply conveys the necessary info to the hooker so that he knows where to lob the throw.
A team that relies on the traditional caller model in lineouts will be denying itself so many potential plays. I just cannot see lineouts still being run as they might have been in the pre-professional era when the caller was king.
The huddle before a lineout imo is to decide and organise the resulting play from the lineout rather than to have a sneaky look at how the opposition is lined up.