Siege machines in deployment order

[matt_t720]

Rather than considering siege machines a hero, they should be placed in the deployment order list.

Being able to place siege machines after giants, for example, would allow a path into the base with wall wreckers etc so other troops such as goblins may enter behind it to attack the core of the base once done with the collectors. This would greatly increase attack success rate & hopefully isn't too hefty of a task to implement.

Thanks.