I feel this discussion would be more productive if we agreed on the changes to the detachment rules. My understanding is that:
1. The opponent is free to charge the parent or the detachment(s)
2. Stubborn, Steadfast, Stupidity, Frenzy, Hatred, Immune to Psychology, Hold The Line is transferred from parent unit to the detachments
3. Detachment countercharges and supporting charges follow the rule of a normal charge (i.e. they do not automatically flank charge as before)
4. Detachments must remain within 3" of the parent unit to count as a detachment
Assuming the above is correct , this will lead to very interesting tactical decisions from both players and Empire could again become a finesse army. It will require a few games to understand what works and what doesn't. However, at the moment I suspect it will be even trickier than before to get any countercharge on the flanks without opening up a detachment's flank to the opponent. There may be situation where one actually wishes to offer a flank charge of a detachment to the opponent as a bait for a secondary flank charge by the parent detachment. However, this could be risky against elite troops. Detachments are typically small and made out of fragile troops. As such, they could easily be wiped out in the first turn of combat. This could be fairly disastrous as it might allow the opponent to overrun in the parent unit (possibly in the flank), or at least reform.