@samuelolavo Shell only handles string values, to pass other types to xo-cli you need to encode them in JSON and use the json: prefix:
xo-cli resourceSet.create name=test-resource subjects=json:'["d301d9ea-9e22-4480-bf40-111111111111"]' objects=json:'["8fb06362-d8fe-598b-f819-11111111111111"]' shareByDefault=json:trueS