I agree with your observations Kevin. I did a little test scenario that pitted these forces:
ORCS Spears Xbows spears Xbows Spears Xbows Spears
Chariots Chariots Chariots Chariots
Rangers Rangers Rangers Rangers
High Elves I wanted to see what would happen. The HE force had 202 points more, but they were charging a line pregnant with spears. The X bows concentrated their fire on one chariot for the two turns before they closed and did a whopping two damage. The turn that the chariots closed they did massive damage (they all had precision so they did three auto hits with seven strength vs. 3 toughness). Of course, nothing got one shotted. The chariots lasted three turns and then the rangers took over to clean up the mess. It was surpisingly touch and go and finally the last ranger went down fighting the last two spear units both of whom were in the yellow. My observation from this experiment is that chariots don't last beyond the initial charge
vs. similarily costed units. Of note is that the two spear units that suffered the initial charge did not last to the end game. Similar points and near tie ending with the win attributed mostly to dice (my insane orky courage checks that make the orcs damn near invincible.
Based on my vast experience garnered during this one game

I think that the biggest problem with the chariots is their lack of damage boxes. IMHO they should have more for the cost or cost less, due to their brittleness. Please note I'm not saying that YMG should change anything, what I am saying is that for me to take chariots they would have to be cheaper. I can't even imagine the situation where they would be a good buy.