How To Silo A Website With Multiple Services Pages?

During episode 90 of our weekly Hump Day Hangouts, one viewer asked about siloing a website having multiple services pages.

The exact question was:

Starting to use silos more because of the obvious benefits and had a question for Bradley Benner or one of the other guys. I have a new client that has a small site that is already established but is fairly small (just 43 pages). It’s a telecommunications site that has a ‘Services’ page that then lists out dozens of services. They do have Subcats already created for just 4 of the services.

So the existing structure goes like this:

Home
– Services
— Service #1
— Service #2
— Service #3
— Service #4

I’d like to create a silo structure using the Services as a top-level. My question is should I make the ‘Services’ page the top level and then create subcategories for the services? Or, should I create a separate silo structure with the services, i.e. keywords I’m targeting and then link back to the Services page already created? It gets a little messy for already established sites as to where you should start the silo structure.
Any help/advice is greatly appreciated.