For me, the more I play, the more I trust the corps AI. So I only detach units when I want them to move faster ahead: ie light inf to occupy buildings before the ennemy. In theses conditions I guess it is understandable that the moral of isolated units (even elites) should be weaker until they get support from their comrades.
Having say that, it could be worth considering the idea of having a "charge" order for corps and units.
BUT with the following restrictions in order to avoid an excessive and non-historical use of this order.
1) Low moral units or corps will still always refuse to charge
2) This order should be used only once in a battle for corps and for 2 choosen units.
3 ) "charge" order should correspond to a "point of no return" meaning that if the ennemy line is not broken after a while, the charge will turn into a dramatic drop in unit moral (and a possible runaway).
In these conditions one will think twice before to use the "charge" order, but it could be very rewarding to have taken the risk at the right moment in the battle. Having this option will help us to mimics historical "special" orders such as : "take (or hold) this position at any price" or or as at Eylau the order to the cavalry to charge the Russian columns.
As a matter of fact, one of the very few things that I still find frustrating in the game id to see a deploying corps stoping its progression for artillery preparation while a gap opens in the enemy line or when the enemy units are weak enough to be pushed back faster without artillery support. With a charge order the AI should let the guns following behind and should increase the cohesion of the corps units. I think this order will also be very suitable for heavy cavalry corps on special occasions.
What do you think : enough historical or not ?