The Orange Pi 5/5Plus use rk3588 cpu, which is big.little, and the 4 A76 cores are about 3x faster than the 4 A55 cores. So `sysbench --threads=4 cpu run` gives 10030.46 events/s, `sysbench --threads=8 cpu run` only increases it to 13578.29.

Which is to say the extra 4 cores are nice, and probably help keep power consumption down, but they are very slow compared to the performance cores.

The Orange Pi 5 / 5Plus boards have far far more features than the RP5 and to me are far more interesting. They have PCIE!

Most importantly though, you can just buy them. I ordered 8 Orange Pi 5Plus 16GB boards from aliexpress and got them in about 2 weeks. You could buy 50 today if you wanted. Good luck getting 3 RP5's, much less 8.