I don't see how you can call this a mis-match, Malignaggi was the IBF champion only 2 months ago till he vacated the belt in order to take this fight, the IBO is not even regarded as a major belt.
The belt that counts the most is the universally recognised ring magazine belt, which Hatton is rated a no.1 and Malignaggi as no.2, hence why they are fighting...
Anyway after Mayweather this should be the biggest test Hatton has had, Malinaggi reminds me of a combination of NAS & Mayweather, he's very cocky and arrogant but also has very good footwork and speed, which is what troubles Hatton most.
Though Malignaggi biggest weakness is he has very limited punch power so does not have the knockout punch too rely on if is losing in the fight.
Due to this fact though I wouldn't conclude Malignaggi is a boring fighter just because he does not have a stack full of knockout to his name, in fact I would say he is a very good boxer because he is capable of winning 20 fights that has all gone the distance.
I would be shocked if Hatton knocks him out as easily and as early as you say, I think your being a little naive and reckon you never actually seen Malinaggi fight. He may look and sound like a bit of a cock but if going by the fight against Cotto who is much biggest and stronger then Hatton, where Malignaggi showed how resilient and durable he can be by going the distance with him and having his jaw broken in the process, then the chances of Hatton knocking him out are quite silm, if he does it would be a major scalp.
For me this should be a really interesting fight, Hatton is fighting at his best weight, against a opponent with similar traits to Mayweather but just not as good, IMO that's a perfect match.