I think that's more suited to a server environment vs a router in this case. I've test 1 vs 2 with the default hash of equal 1 or weight 0 1, and the default of 2 pairs with equal 2(spreading the hash more even without a hash key) is more profitable. 1 pair seems cause more cpu usage on only 2 cores vs across them. I guess the jury is still out on that. My tests have been from nperf.com and waveform.
new driver error from that link 
Cannot get RX network flow hashing options: Not supported
This means it's not spreading across the cores effectively.