Work authorisation means the permission to work from the authorities. There is a 'work permission 'authority... in German it's something like 'Arbeits amt'...
It probably is easier to get a work permission for a dependent L than a new person outside the country (at least, I felt like the situation was pretty straightforward when mine was done) - but it is the employer's responsibility, and they may or may be able to match you to the requirements.
Basically, the person still needs to be taking a specialist job, for a position that cannot be filled by a local (Swiss or EU) candidate. They have to be offered an acceptable wage (the authorities check this, if it's too low they will tell your employer it's too low)...
Tinderstick, I hope you're not going to pay your lawyer a lot of money for what is essentially paperwork that your wife's employer is going to do - if she is specialised, then the permit should not be a big issue (I'm assuming minimum 3 year bachelor's degree and probably postgraduate)...
I hope it runs smoothly. I was in this situation and successful, and it was all approved within the allotted time frame. The authorities told my employer that it would be dealt with within 3 months, and we also had a 'start' date which was based on the previous staff member leaving, and they met our deadline and I was able to start work on that day...