You could use a 1-liner for each. Not quite as readable, but fewer characters overall.

Shaman 1:
/cast [target=cloverine,nodead][target=clovine,nodead][target=clovianas,nodead][target=clovina,nodead] lesser healing wave

Shaman 2:
/cast [target=clovine,nodead][target=clovianas,nodead][target=clovina,nodead][target=cloverine,nodead] lesser healing wave

Shaman 3:
/cast [target=clovianas,nodead][target=clovina,nodead][target=cloverine,nodead][target=clovine,nodead] lesser healing wave

Shaman 4:
/cast [target=clovina,nodead][target=cloverine,nodead][target=clovine,nodead][target=clovianas,nodead] lesser healing wave