Call me nuts but I went through all of the well over 100 Geekbench entries.
All iPhone 11 are 3844 MB
All iPhone 11 Pro are 3759 MB
All iPhone 11 Pro Max are 3740 MB
There are no 6 GB models, contrary to popular rumour.
There are two clock speeds, 2.66 GHz and 1.86 GHz. I think they may actually be 2.6666666667 and 1.8666666667 GHz. Because with those numbers, the lower 1.86 GHz clock speeds is exactly 70% of the higher 2.66 GHz. Apple does have a low power battery mode that you can manually toggle on and off, so this may be reflective of that. However, on my 7 Plus with A10, while toggling on low power mode markedly reduces performance, it doesn't change the reported the clockspeed in Geekbench 5. Perhaps Geekbench reports clock speeds differently on A13, I don't know.
GB5 performance at 1.86 GHz is roughly only half (not 70%) of the higher 2.66 GHz. Multi-core vs. single-core multiplier is 2:1 at 1.86 GHz, but about 2.6:1 at 2.66 GHz.
Most of the speed variation concerns multi-core. Single-core speed is quite consistent, but multi-core has a wide range. Throttling? Background processes?