Of course implementing such a move is not easy with an opponent who will move to negate this.

A shorter battle line will take less time to wheel around though and i based my theroy on the reasoning that the enemy line will hold it's formation and length.

In an online battle its whoolly unlikely that people will allow themselves to be compromised like this i agree. In which case i use skirmishers to hold the line facing forward while my infantry line executes the above tactic. The replay of this is available in the heavengames(RTW) downloads section under mailed celtic fist.