The yari cav doesn't necessary have to beat the GG, it's winning the charge. On a large block to large block charge, the advantage yari might not take out enough GG men to win the entire engagement. On a small thin line vs thin line however, the charge might be detrimental enough that the yari can beat the GG
Got your email and will be looking as soon as I am finished here now. Thanks!

We did try the test with switching host and attack/defender position in the past. Out of 6 matches, I only loose charge advantage in one match. So it's inconclusive as to whether host or attack/defender position do effect or not.
I will be doing an intensive testing this morning, to prove what I can (have several theories).

Until then, consider that the game is actually only processing one action at a time, and if two units are charging each other, the benefit of advantage can only be given to one of the opponents at a time, with the result affecting the numbers of the other, so that even when the second unit has their advantage added, they are already suffering a loss of men and potential to benefit from it.

Be back soon