No collective bargaining rights, so he has the ability to alter salary amounts. Now he can reduce salaries of teachers and keep the teachers which were going to be laid off employed without increasing or decreasing the overall budget allocation. No fiscal impact. Sounds pretty simple.
The problem is, he's said he's going to use this to close a multi billion dollar gap in the budget. If he does, no matter how you twist it, there is a fiscal impact. From what I've read of Wisconsin law, fiscal impact isn't defined. So, in all probability, a judge will have to define it. Whether it means no impact on the overall budget allocation or whether it means an impact on any and every state function, we'll have to see. But even under your scenario, if the budget was billions short and this one action will cure that, then there is a fiscal impact on the overall budget allocation.