the conquest rules state that for multidials all actions for movement may be combined into one so how would you handle the charge on the chariot?

can you add the sides to the charge ability??

In Conquest you assign a Move action to one section of a multi-dial and can combine all of the movement values for that action (this works like a formation: one action to use as many of the speed values as you choose, but then those sections can't be givn any other actions.) If you use the Charger's front section, you can either double that value or move and attack. So you could move up to 12" or move up to 8" and attack with the front by combining the speed values of all three. Does that help?

Ok excellent.

It just didnt seem legal though because (I know I have to ask this)

if I can move up to 8 inches and attack , why cant I then just move 16 by activating charge too?

Charge provides the options of move-and-attack or move-double-distance. Movement SAs (other than Aquatic and Flight) only apply to the section they show for: that's in the multi-dial rules.
So the War Wagon has these options: left side=2", right side=2", front equal 4" and attack or 8". So your maximum options are 2+2+4 for 8 and attack, or 2+2+8 for 12. Does that help?:)