Currently you can't create multiple service.discovery templates as only one service.discovery key is allowed, even if it's used in two different templates linked to one main template.

https://www.zabbix.com/forum/zabbix-help/363543-windows-service-discovery-with-different-regex-and-trigger-severity

Allowing duplicate service.discovery keys when linking templates, for example linkin service HIGH and service Average templates to Template OS Windows would allow different trigger serverities during service discovery with different rules.