not sure what you meant to say here
but I'll add to
@bigredfish that the two models are also different by the amount of cams that supports FR or, of you do the FD by the cam and FR by the NVR, the 52XX cam use all cams for FR.
BUT at the moment. the FR implantation is really BAD. I'd suggest you'd read some of my other posts about it.
While the HW capability is nice, the Dahua SW implementation makes it completely useless.
I'd be more that happy to write something else if and when they'd make a big change in the concept and SW but for now: get away from it.