Kowalski, analysis!
Havik has a 1.22x AP advantage (furthered with his morning star) while Kim has a 3.41x lifting strength advantage. Kim is trained in a higher confirmed number of martial arts but Havik's unpredictable fighting style would likely throw her through a loop. That said, in close quarters combat, Havik would have a hard time if Kim were to restrain him with her superior lifting strength.
Kim's arsenal is larger than Havik's, the grappling hook, jetpack, and rocket roller skates would give her superior travel speed and control over the battle field. Her knock-out gas gives her a win condition and her magnet wrist device could disarm him of his morning star.
However, Havik has a much better ranged attack with his energy projection and his Low-Mid regeneration means that Kim's punches and kicks wouldn't leave permanent damage and would make it hard for her to knock him out. His body control would also catch Kim offguard and potentially allow him to escape any restraining holds (via breaking bones and contorting his body). While both have Superhuman stamina, Havik shrugs off more crippling injuries than Kim.
So, let's look at both of their options. If Havik decides to play a ranged-game with his projectiles, it wouldn't be hard for Kim to dodge them (like she does with Shego) and her gadgets can allow her to close the distance. So the fight would ultimately come down to who would win in a close quarters fight. Kim's best option would be to use knock-out gas on Havik, something he can't resist and probably wouldn't see coming. Havik's best option would be to outlast Kim with his healing factor and superior strength/durability.
Now, which is more likely to happen? Well, Kim doesn't use her knock out gas very often, only using it when she's desperate (and even then not consistently). Havik's unpredictable fighting style would make it hard for Kim to keep up with him, and his body control might even disgust her. While the latter might motivate her to use knock-out gas, it might also distract her from the fight at hand. Not to mention that she might not even get a chance to use it if she gets trapped in one of his
air combos.
It's close, but I'm slightly leaning towards Havik.
