First of all: thanks for the report, these are the most valuable posts in this thread.
Secondly: Someone already told you about Olynder and MW's against Sylvaneth. I'dalso think that Spirit Hosts against SoD are your best bet, combined with spellcasting. Get some cheaper solid battleline and put your casters behind it. Deny his magic and MW him down.
Maybe an unfavorable match for NH, I don't know, but these things happen, since some armies are the paper to your stone.
Thirdly: Try to get kowledge of what your opponent can do. Read the warscrolls yourself. He probably didn't get something wrong, but some opponents do in super onesided games. So if you think something is abnormal....go check it yourself.