Countering FU champions with HC

I was playing as Indians vs Vikings and Japanese. Thanks to some great answers on my previous question, I was able to hold off the knight rush and boom. Then I started getting attacked by champions of both civs, backed by skirms/arbalests. Per the wiki, " Again, Hand Cannoneers easily deal with enemy infantry, so the player must use them.", so I went into HC with halbs in front. It didn't work, the champions cut through both, unless I committed 5+ HC per champ.

What am I doing wrong, I.e. is it a micro issue or should I mass larger numbers of HC? Research all armor upgrades (I didn't get ring archer)? Conversely, is the unit choice itself wrong?

Thanks a lot!