[{"id":"1","name":"Alice"},{"id":"1","name":"Bob"}]

db.collection.aggregate([{"$unionWith":{"coll":"collection","pipeline":[{"$documents":[/** documents to be inserted here*/{"id":"1","name":"Alice"}]}]}},{"$setWindowFields":{"partitionBy":"$name","sortBy":{"id":1},"output":{"idRankInName":{"$denseRank":{}}}}},{"$match":{"idRankInName":1}},{"$unset":"idRankInName"},{"$merge":{"into":"collection"}}])