More a level of direction Mack. - You may have a few paramedics at a scene, and an ICP will arrive. - The ICP won't neccessarily take over the Commander role, as their skills in treating / triage and different levels of protocol may be more valuable. Same as some area managers or CTL's who I think most often are also ICP's (boredmatrix might be able to confirm?)..
But sure, if the sheit was hitting the fan, the likes of an RTL (baseline manager) or Area Manager etc would step in and take the scene.