Info: Sieges and Army setup

[Gurthang]

Hi everybody,

looking for some info from the professionals out there

When it comes to storming a castle, has the Army setup anything to do with the deployment of the besieged army, or is deployment entirely determined by the computer during sieges?

I have lots of wizards and 200+ troopers in my soon-to be stormed castle, and I would like each of them to cast "Marble Warriors" (range 10, area of effect 25) over as many soldiers as possible. How can I ensure that they the wizards will be within range and that they won't cast the same spell over the same soldiers?

Should I assign each wizard to command 25 soldiers, in order to encourage the computer to deploy them in their vicinity?

All help appreciated!!