Citations cannot be compared across fields. RR is an quantitative macro guy, SH is an applied theorist. Within their fields, SH’s GS record is at least as impressive as RR’s.
This is another example where publication outlets are a much better measure of quality than citations. And this clearly shows: SH has mostly published in noname journals, RR consistently in decent ones. Hence RR>SH, but you can’t see this from citations.