Dahua NVR with Lorex or HikVision cameras

when you only want to record, sure. you can just add the cams as onvif. BUT if you want to use special functions like IVS , you should use the same brand. sometimes the nvr cant use IVS via onvif. dahua and hikvision uses their own communication to use the cpu of the cam.
 
Lorex cameras are "mostly" OEM Dahua. You just need to change the default Lorex ports in the camera firmware to match the Dahua NVR first. Then they work using the native Dahua protocols.