His major contribution was on axon pathfinding and growth (axons are long cellular extensions from neurons that form functions circuits in the nervous system) and he made those discoveries when he was a postdoc and when he was just starting as an independent PI, but they are not ground-breaking. His laboratory continues to do high-quanlity work over the years. I probably would put him at the same level, or slightly lower than, Shi. If not impossible, it would be very hard for Rao to find a Chair, let alone a Dean, position in a top-50 university in the US. In their respective fields, Shi may have better name recognition than Rao.