Maybe it could be an issue with the level range. I feel the game well balanced with my char at 150 but same mobs destroys or two shots people at +300 looking at some videos.

Prometheus + node/container exporters. + Grafana for dashboards I haven’t touched zabbix in years but last time it didn’t support very well dynamic scalations. Also all of them are focused on monitoring infrastructure, you need to pay if you want APM or UX.

Enterprise level, for APM I like datadog, much better than NR. For UX we use acoustic tealeef.