I assume your looking for a more populated server? Shadowlands I believe is actually more populated than Jedi Covenant by a small margin. http://www.torstatus.net/ This is website to check population of different servers.
The latency your seeing on Harbinger seems to be out of the norm and makes me wonder if it wasn't a fluke such as a problem with your internet at the time. I usually see on average 70-100 ms on Harbinger and 35-50 on Jedi Covenant playing from Michigan