Siege Mage viability

[TheNivMizzet]

I'm about to start a new pathfinder game and was given freedom to use any resource as long as it doesn't break the game. Then I saw Siege Mage and thought the words "I want my Wizard to ride a ballista." and wanted to know how much experience people have with the archetype, and its viability in a game. It appears to be a archetype for the GM to power out siege operators for the NPCs, but if I can get a mobile Ballista on the back of a cart, hire a low level mook to reload it on his turn, I can pump out consistent damage and have fun. But if the archetype falls flat or people have had problems with it before I would prefer to know now rather than be hit with a bunch of penalties I'm currently missing.

[Fouredged Sword]

Eh, siege weapons don't do a ton of damage actually. By the time you have practical means of hauling one around, monsters will just AOE your loading team and kill them all. Better to spend the money to buy a wand of fireball.