Hi,
Thanks for raising this.
Broadly speaking, yes, 3-node should provide higher indexing throughput.
Indeed this is the case with other tracks: nyc taxis, pmc.
However, one difference between the 3-node and the default benchmarks is that the former has 1 replica, which reduces the initial indexing performance (see also here). Additionally http_log, as well as geonames and geopoint have a very small doc size and get impacted more.