Spent quite a long time with bitcoin-abc-0.16.2 and armory 0.96.3.991 and trying to get it to work.

This combo throws in the bitcoind log.
2018-01-04 21:34:48 PROCESSMESSAGE: INVALID MESSAGESTART version peer=0

However, bitcoin-abc-0.16.1 and armory 0.96.3.991 allows the connection to happen:
2018-01-05 07:11:02 receive version message: [127.0.0.1:34586] Armory:0.96.3.991: version 70012, blocks=-1, us=127.0.0.1:8333, peer=0

Just a heads up to others. I believe something changed in the bitcoin-abc repo around 12/3/2017 surrounding this PROCESSMESSAGE output.