I imagine that if you had another player who was going to be your wingman then it would be a case of talking with them [comms etc]. NPC wingmen can be found in the design archive.
The comms section in the DDA mentions a possible upcoming icon system for quickly communicating with other player wingman. Voice comms will also be extended to cover groups on the same side. There is also a section on wingmen you'll be able to hire.
