Before I get jumped on here, let me just say this is not putting down anyones training/SOP/SOG/exp, or anything of that nature.
Not sure how you train, but when my department trains, we usually use the bigger guys as the victims. 3-4 people IS NOT enough for a rescue, unless you are lucky enough to be near a window, or door. 3-4 people may be able to rescue someone if they are dragged out of the building, but if you have to carry up/down stairs, out a ladder(need more if they are unconscious), or thru a roof opening. Realisticly, you are going to need atleast 8 properly trained members to properly complete the task. The RECON team, is basically that, a team to find the downed firefighter. If the victim is conscious, and is able to walk, they get him out. If he is unconscious, they turn his airpack into a rescue harness, and drag him(if they can) to safety, or as far as they can. Once the recon team finds the victim, they immediatly call command and report where the victim is, if he is conscious or not.
Everyone does things differently, so dont take this as "this is the only way to do it". Trust me, it is not, but this is the way we use it, and it works very well for us.