If you're permitting, or have, traffic site-to-site, i.e. other than pure hub-and-spoke, you can't easily control the MPLS egress congestion, other than within the MPLS provider's QoS model. This negates much of the benefit of shaping at your large bandwidth site.
If there is no competition for MPLS egress bandwidth, you can effectively deliver QoS via shaping at your hub, but if the MPLS provider offers an adequate QoS model, it's usually simpler to just use it, especially to maintain.
If you were going to do it, using one class-map per destination site with a shape command would work. You can optionally prioritize with a child policy.