If I use your line-up:
Thor > Superman (magic)
Strange > Fate
Silver Surfer > Hal Jordan
Prof X > Martian Manhunter
Black Bolt > Wonder Woman
Hulk < Flash
Namor >>> Aquaman
Now, it can goes in different ways. I see different scenarios:
1- While Prof X is gonna overpower Jon Jon'zz, Flash stop fighting Hulk for 2 seconds to wtfomgpwnz the good ol' Chucky, and then, come back to fight. It's leave a Manhunter free to go help Hal Jordan against the Surfer. When the Surfer is down, Hal and Manhunter goes after Thor. With Superman, the trio obliterate the Marvel's survivor.
2- Silver Surfer take the yellow sun energy out of Sup while fighting with Hal Jordan. Thor and Surfer then pummel Jordan. Thor go with Strange against Fate, and Surfer pulverise Flash and the Manhunter. Marvel in a stomp.
3- Strange call on the Vishenti to bfr Fate. After that, he kill with ease Superman. Thor go help his buddy Black Bolt and Strange help Surfer.
The most vulnerable caracters are Prof X and Superman. Superman can be kill by 3 member of Marvel (the three first).
Superman vs Thor - Depending on which version of thor this is superman stomps. Yes Superman has a magic weakness but it isnt as great as everybody thinks it is. Superman's resistences have risen so high over the years that he is almost unstoppable. If this is Endgame thor thou he could handle superman much like Classic Darksied could... With a causaul back hand slap.
Dr. Fate vs Dr. Strange- No 2 ways about it, dr.Strange completely dominates Fate. There are only 3-4 version of fate that could even give Strange a good challenge. (There is one that could wtfpwn him thou so beware.)
G. L vs Silver surfer- With the exception of Hal SS shouldnt have any problems over powering (or at least outlasting) pretty much any Gl.
Martain Manhunter vs Prof. X- Prof.X's only hope is that this is a long distance battle of the minds because jonn could crush him like a ant in 2 seconds flat. Even in a battle of the minds I see Proff. losing more then winning.
Wonder women vs Black bolt- Black bolt has absolutly no chance in h2h with wonder women. His only hope is to Full out scream and hope she doesnt get back up.
The flash vs Hulk- Hulk has no chance at all here.
Aquaman vs Namor- Auqaman has a HUGE durability Edge here. Namor (while stronger) isnt as versitile and would ultimately lose. This would be a battle worth watching thou.
I give it to Auqa to simply outlast namor.
Marvel loses 3 people within the first 2 seconds. MM mind rapes Prof X and boots him off the planet and before BB can open his mouth WW lassos him and commands him to be silent (if she hasn't already snapped his neck). Then WW runs over to Hulk and touches him to sleep.
Doesn't Dr. Strange have constant defenses up for like a speedblitz by the flash or someone? If so Strange can just freeze time or something and defeat everyone in DC. He beats Fate by just being better. Even without a time freeze, Strange can take them all out, sends em to another dimension and kills them 1 at a time.
If he doesn't have an automatic defense then one of the speedster's takes him out and Fate takes out everyone else. (or they can fight one on onish and they'd still probably win with a little help to hal with surfer)