Yes but theres one advantage round robin has (a BIG one) over using castsequences.

/stopcasting
/cast Thunderstorm

With roundrobin this will stop casting on ONE toon and then thunderstorm immediately. Without round robin you're stuck with:

/stopcasting
/castsequence reset=45 Thunderstorm,,,,

etc.

This means every time you hit it, it will stop ALL casting from ALL shamans and then cast thunderstorm - severe DPS hit.