Fixing the shield bug will make inf better on cav when pinned but if the "plough of death" is not removed, then it won't mean squat because the spearmen won't have a chance to even get off two stabs at the cav.
Ah but the shield bug being fixed will also make inf better at facing the charge, as the shield bug even counts agianst infantry when they are charged. Even with the rather crude shield bug workaround used in mods infantry and much more able to receive a charge.

And cav charges are going to be weaker in 1.2.
I don't remember this working in RTW, I think in Rome when you tried that the cav got owned, I'm not sure why...realistically that would happen but its a good gameplay mechanic.
I think it was in RTW as well, i am not sure.