As I read it, an evading BG has the choice (players choice) whether to turn 180 degrees or 90 degrees when charged, if the evading group evades "in the direction of the charge". I don't understand why it's the players choice. E.g.:
AAAAX
.BB..
.BB..
A is a BG of 4 heavy cav facing down, B is a BG of 4 LH facing up. The LH decide to charge the Cv, declare direction. As I read it, the Cv can decide not to turn 180 degrees, as seems logical, but can also choose a 90 degrees turn. Let's say the Cv decide to evade "in the direction of the charge", turning 90% (to column) and then wheeling at point X in the direction of the charge and moving their MVD. Now, the LH most likely bypass the Cv

Is there something in the rules preventing this?
Thanks