You can't extend a client relationship to your colleagues that you've not yet established. Sounds obvious, yet many lawyers try to do just that in the early stages of a sale.
Here's how it happens.
Your internal Guide arranges a meeting with you and a Buyer or key influencer. You immediately invite (or succumb to pressure to include) other lawyers from your firm, each of whom wants a chance at partial credit if you get the business. Once there, each will feel a powerful need to display his or her expertise. The result is a series of people talking about themselves.
This is counterproductive. The prospect doesn't know you yet; he or she is meeting you only on the strength of the Guide's "blessing." Your goal for the meeting is to establish trust and credibility (and thereby affirm the wisdom of the Guide's recommendation and the Buyer's decision to take the meeting). If you include a colleague, courtesy requires the Buyer to split attention between the two of you. Two people cannot create relationships with a third simultaneously. You won't create two relationships; you'll create none.
Instead, make the first contact alone. Establish yourself and identify the issues driving service demand, then later, if there's a clear benefit to the prospect by doing so, introduce your colleague as a "content specialist" whose expertise will add the requested value to the next meeting or phone conference.
The biggest reason for going alone on the first call: Few of your colleagues will have learned how to conduct a proper sales investigation. Instead, they'll still be oriented to the pitch model. Even if you explain how you intend to conduct the meeting and why, you won't be able to control them because they don't know why it's important to do it that way, and the consequences of not embracing the discipline you urge.
Listen as buyers tell you why it's time to dump the pitch model in favor of a disciplined sales investigation focused on helping prospects make good decisions.