The part where Mounted Hussars and Vehicles differs is the rules about each type.
For mounted units it's written they must spend their actions simultaneous and focus on the same action. So Mount can't move while Rider shoots. They either both move or both attack.
Vehicles on the other hand got the following special rules:
A Vehicle is able to use a move action to break from Close Combat no matter what it is.
While performing a Move action the vehicle if single crewed is able to fire.
While performing a move action with a multi-crew vehicle, all crew members must perform their actions before the drivers next.
Both gives the opportunity to move away and fire at the same time as is written.
It is written that they are able to spend a move action to break away, and while doing a move action they may also fire.
This is written on page 92.
For mounts it's stated (on page 42) that the rider and mount must perform the same action.
On Mounted Hussars it's only stated as a Special Rules that the Mount is able to automatically break from CC. But to break from CC you need to perform the action break away which results in a move, in this case which let you automatically succeed the roll and you move.
To try and sum my point up:
1. Mounted troop is in close combat.
2. Spends 1 action to break away, because of special rule there is no opposing roll that would let the enemy keep it at bay.
3. The mounted troop is granted it's MV in inches to go anywhere it like. This must be spent by both rider and Mount to perform the Movement/Break Away.
Note: This is still 1 action point spent to break away, it's not 1 action point spent to Attack.
If you don't declare you break away, which is a action, your still stuck in close combat and can't move away. And while in Base to Base contact with a enemy you can not charge.
1. Vehicle is in close combat.
2. Spends 1 Action to perform a Drive action as stated by the rules, which let it automatically break CC and move away.
3. Since it's 1 Drive action it is also given the opportunity to fire it's weapon as stated by the rules with vehicles and Move Actions.
Note: This is 1 Action point spent to perform a Drive action, a special action for Vehicles. In essence the vehicles Move action but with it's own special rules.
Now just for note: This is how it seems for me when I read the rules, it is my belief how things should work given the information I got.
