If the amps are sonically identical, I’d be inclined to wire them in a vertical bi-amp configuration. One amp on the left, one amp on the right. You get the benefit of improved separation and soundstage, and each channel has it’s own power supply. There could be some improvement in clarity as well. Many of the same benefits of monoblocks.
You can try a horizontal setup as well, and see which you prefer. There are pros and cons with each.
If your subwoofer has a high pass filter, you could experiment with limiting the low bass frequencies to your RP-5s too.
