Technically, either one should be able to take SM alone (though SM is Venom is always a good fight), but they're bad guys so it never works out that way.
SM has only marginally faster reflexes and intelligence on his side...but it doesn't help him much because he's outmatched everywhere else. The symbiotes destroy him.
This one would be difficult to determine as all 3 are all powerful fighters with unique super abilities but for some unknown reason I think Spiderman would actually pull this one and win against the 2.
__________________ "The darkside, Sidious, is an illness no true Sith wishes to be cured of, my young apprentice .."
Without a concrete reason why, I'd have to disagree. With prep time, sure, since Spidey could get a hold of a disruptor/harmonic frequency whatsamajig to stop them, but in a straight-up fight I'd be pulling for the wall-crawler but a win would be highly unlikely.