One approach to mitigate the connection problems for tpcc would be to utilize a connection pooler like pgbouncer or yandex/odyssey. It’s certainly more complexity.

Another suite to look at is sysbench. It’s very flexible, for better or for worse, but it can allow you to create an interesting mix of queries at different scale factors. For something like this where you’re going head to head with Postgres, having more dimensions with more benchmarks isn’t going to hurt. Ideally you’ll see a nice win across the board and get an understanding of the shape of differences.