@Dave Lonsdale
This is, what you have in your cameras:
SD3282D-GN 1/3" 2MP
HDW4221EM 1/3" 2MP
SD22204T-GN 1/2.7" 2MP
SD29204T-GN 1/2.7" 2MP
HDW4300C 1/3" 3MP
starlights
HFW8231E-Z 1/2.8" 2MP (IMX290)
SD59225U-HNI 1/2.8" 2MP (IMX290)
HDW5231R-ZE 1/2.8" 2MP (IMX290)
So basically you were comparing old era sensors with first generation of Starvis, which is IMX290. I wouldn’t expect enormous difference between these, but obviously there should be clear distinction. Sensor performance is not about image brightness, but rather image clarity (noise level). If old sensors were described as 0.05lux and new one as 0.005lux, it means that if you rise GAIN of new sensor by about 3EV, you should get similar noise level. In other words, if an old camera was doing well at 1/30s exposure, the new one should achieve same quality at around 1/240s exposure, while maintaining same image brightness. The scale is logarithmic. Of course lens brightness also counts here.