fanaticism and losing Cavalry Charge bonus

[Jagger]

In Napoleon's Russian Campaign, I noticed that Russian troops have a fanaticism rating.  I searched the manual and not a word about fanaticism.  So I am wondering What fanaticism does and when does it apply?

Reading the manual, I came across these descriptions concerning cavalry charges:
• The defending units must not consist entirely of Infantry in Square
formation with Leaders and/or Cavalry. However, if only Skirmishers,
Artillery, and Supply Wagons occupy the defending hex with Infantry in
Square, then the charge is negated.

Reading this section, I could feel a headache coming on.  I tried translating and came up with this:
-The charge bonus does not apply if defending units are composed entirely of infantry in square with leaders and/or cavalry.
-The charge bonus does not apply if defending units are composed entirely of infantry in square with skirmishers, artillery and supply wagons. 

However it still does not quite make sense.  I really am not sure why they didn't simply make it one sentence in which squares with leaders, cavalry, skirmishers, artillery and supply wagons negate the charge bonus.  Or just say squares negate charge bonus regardless of other units sharing the same hex. 

So did I get this right or am I still missing something?