WOL not working with two NIC’s

You need to send the packet to the broadcast address of the network. You can't send it to 192.168.1.127, because the PC is powered off and so this IP is not owned/bounded by him. Set it to 192.168.1.255

You'll want to add a persistent route to the routing table for the default gateway of the 172. interface with a lower metric than the route that was added for the 10. interface. Example:

C:\>route print
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 ff ff ff ff ff ...... Intel(R) 82567LM-3 Gigabit Network Connection
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0        10.10.0.1       10.10.0.2       20
          0.0.0.0          0.0.0.0       172.16.7.1     172.16.7.51       30
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
Default Gateway:         10.10.0.1
===========================================================================
Persistent Routes:
  None

I would type the command route -p ADD 0.0.0.0 MASK 0.0.0.0 172.16.7.1 METRIC 1

Source

Re Edit 3:

You need to make the metric lower, not equal. When your routing table has 2 routes with the same metric, windows will load balance across these 2 routes. That means it will send 1 packet out the 172 interface and the next out the 10 interface. This is why you have to delete your other route. Go ahead and make the 172 route persistent with a metric of 1 and you should be all set.