In high-risk battles like those in which you use EI to stop chariots, I would keep the general right behind the critical EI formations. After, as long as the chariots are free to move your own cavalry are immobilised. So why not put your cavalry where they're are useful?

Also, with regards to the bonus against the chariots, read the Brutii thread... there's one entry that hints that the bonus may apply to melee combat too.