Very interesting post!
I think it all comes down to (as always) people's knowledge of and belief in, the Bible.
I am a believer now, but wasn't most of my life. I didn't get the Bible at all, but in time and in reading it, I do now.
This is the perspective from someone who believes in the Bible...
the word "coven" is not used in the Bible, therefore, we cannot use our own words or definitions regarding it.
"Coven" is referred to as "an assembly of 13 witches" by most dictionaries. Jesus was God- not a witch. The others were men, not witches. So we can't really say they were a coven.
Jesus performed miracles, according to the Bible. He was God- the Creator of everything (according to my beliefs). He did not use incantations- he just touched people and told them to "rise" or "do you believe? then see...". Because He was God. People who practice Wicca think they get their "power" from words, books, and some force that is not the God that is spoken of in the Bible. That, it says, is "magic". Witches use spells, Jesus (God) used nothing but Himself.
Moses used a staff to part water, because he was doing deeds for God- he was freeing a people that God promised to deliver freedom. It wasn't Moses, but he called on God to do that. But again, it isnt seen as magic, because it is from the Creator, the Father.
Again, this is just based on my beliefs, and the Christian beliefs.
I have friends who are Wiccan, so please dont take this as me bashing anyone else- I am just answering where we come from.
Its so hard when someone doesnt know or believe in the Bible- because it cannot be proven until death or the end of time. Thats why it is called "faith".