well, I know that it doesn't make much sense. This setup was made to "balance" the traffic coming in to the machine. I know that there's not much difference between one NIC running at, say 400 Mbps, or two NICs running at 200 Mbps each which will also be 400 Mbps, because the machine can't handle more traffic (data (backups) is received via network from other machines and written to disks)...but as I've already written, this wasn't my decision...
Your decision or not if you are the one to "implement the fix" then you should
suggest something that will work and not try to get something else to work that
won't work. At that data rate you would probably have more issues with disk
I/O anyway so a load balancer sounds like a better solution.
Good luck.