Wide field of view means limited field for identification. A 2.8mm lens will give you a wide field of view but will only identify, reliably, within 15 feet or less of the camera. If the camera is already 15 feet up a 2.8mm lens is useless for identification. Even a 3.6mm will be pretty much useless at that height as will a 6mm lens. All you will identify is the tops of heads.
Amcrest is an OEM brand of Dahua. They're lower priced because they have features stripped from the firmware and are made with lower quality components and housings. I would recommend sticking with Dahua or Hikvision since both are quality, semi-pro or pro grade cameras. You get what you pay for and, as looney2nes says "buy once cry once". You've already experienced low priced performance with Reolink and are replacing them, why do it for yet another cycle?
Remember that every camera needs light to see be it visible, white, light or infrared light. Every camera needs to be "tuned" to produce the best possible picture for the exact location it is installed in. Settings for one camera will not normally apply to another camera even if they are the same make, model and firmware.
Night vision is a function of the sensor size versus sensor resolution. The higher the resolution the bigger the sensor needs to be. The short answer is don't chase megapixels, chase sensor size.
The smaller the lux number the better the low light performance. 0.002 is better than 0.02
The smaller the "F" of the lens the better the low light performance. F1.4 is better than F1.8
The larger the sensor the better the low light performance. 1/1.8" is better (bigger) than 1/2.7"
The higher the megapixels for the same size sensor the worse the low light performance. A 4MP camera with a 1/1.8" sensor will perform better than a 8MP camera with that same 1/1.8" sensor.
Disclaimer - These sizes are what the manufacturers advertise and may, or may not, be the true size of the sensor in the camera.
720P - 1/3" = .333"
2MP - 1/2.8" = .357" (think a .38 caliber bullet)
4MP - 1/1.8" = .555" (bigger than a .50 caliber bullet or ball)
8MP - 1/1.2" = .833" (bigger than a 20mm chain gun round)
Note that 3MP, 5MP and 6MP cameras are not on this list. That is because there is no camera out there with the proper sensor size to produce a good night video that includes motion. To get good motion captures the exposure time, shutter speed, needs to be 1/60 second or better 1/120 second. A 5MP camera with a 1/2.8" sensor will be basically useless at night compared to a 2MP with that same 1/2.8" sensor.
