Midnighter's striking ability isn't just about what strength level you want to guess he's at. He knows how and where to strike with the strength he has to get the effect he wants. He doesn't need to be stronger than a character to break them down physically. When he takes it to Hawksmoor he's doing more than just using his momentum against him. He makes a blow to the back of his head and knees him in the chest between the images that were posted above. That's actually their second fight and in the first they exchange solid blows to each others heads before the fight is interrupted. Despite not have strength anywhere near Jack's 100+ tons or his incredible durability, Midnighter is able to fight him fairly well in h2h. And that's because he can make the strength he does have count. It's easier to accept if you see Midnighter like Karnak or Karate Kid.
Wolverine's brawn isn't much to write home about when you consider that Mr. X, who was human and didn't have move prediction anywhere near the level Midnighter is working at, was able to school Wolverine without much trouble. Add in Midnighter being able to hit well enough to drop Hawksmoor, Maul, Sebastian, and others, and Midnighter should be able to handle him. As for Deathstroke being a teambuster that can take down Justice League level beings, even pretending he's beating up Superman-level characters with any regularity and not just picking on children most of the time, Midnighter does the same. In the fight shown where he takes on Apollo, he's also taking on the rest of The Authority, and he's doing it easily. This is the guy who only starts to feel mental strain when he's working on fighting literally a million enemies at once. He's the sort of guy who jumps a couple dozen superhumans at once and runs that fight so well that he can maneuver every one of them into standing exactly where he wants so they can be blasted away by precision lasers from space. A character that will fight dozens of enemies at once and take pride in a rip in his coat being the closest they ever got to touching him. Midnighter's no stranger to fighting groups.
You're right about blood splatter not being the final word on a strikes effectiveness, but when you have something like the instance with Apollo, where the blood goes right along with a direct comment about damage being done to the area where the blood is coming from, it's more than just random splatter for effect.