My own experience is that non payroll based employees rarely prove to be as effective as one imagines. The energy and dedication of consultant can wane if there are not quick wins, or alternatively the risks in work that the consultant wants to pursue can be outside of the box of what the Firm actually wants to pursue.
At LCC we have attempted collaborative engagements from time to time, but despite best efforts, dedication of resources and much time / money invested the recoupment from such initiatives is marginal at best.
In many ways this is similar to a 'channel' initiative. Not all channels work. With consulting services the risk are understandably higher given the intangible nature of services delivered. As such I would recommend that you wait until you can hire full timers - and approach any collaborative effort with caution.
