It won't work at all if you set the proxy IP or the port wrong.To really convince yourself though, open the console mode (in the help menu on Bitcoin Core I think) and you'll get a breakout window with a tab showing you the IP's of the nodes you're connecting to. The right half of the nodes tab should show further details for each node. In the further details, you'll see the node IP and the forwarding IP that each node uses. If all the forwarding IP's are the same, you're either not on Tor or really unlucky/lucky. If all the forwarding IP's are different (or all but 1 or 2), and/or you see hidden service IP's (e.g. fhgsnegahskfgwd.onion), you're using Tor.
Also, there's a setting in Armory to route all traffic (i.e. not only the traffic going between Bitcoin Core and Armory) over Tor. I would use that option (in Armory settings).
Thank you kind sir!