Loki as the best H2H as he has had the most screen time but I always thought it was heavily implied he was by far the weakest of the group in terms of strength and H2H ability.
Even if you account for her Strength feats the only one Loki hasn't replicated is casually kicking a large trailer easily.
But H2H Loki has better feats. Destroying Shield Agents including Hawkeye and Fury. Which is better than Sif taking out a bunch of guys from a Biker gang.
He has also gone H2H with Thor which is leaps and bounds better than anything Sif has done H2H related.
I mean like I said I always thought it was supposed to be pretty clear that Sif was the weakest of the group in those areas relying more on deception and tricks but if you look at pure H2H feats Loki does seem to have the better ones.
Have to agree with Newjak. I personally think that Sif is a better fighter, I felt like it was implied that she was the best fighter of the bunch (after Thor). But Sif has too few showings. Loki went up against Thor and actually landed hits. Sif took on a seductress. Until we see more from Sif I'm siding with Loki on this one.
It's supposed to that Loki is the weakest of the group in terms of H2H and strength not Sif. I think most people will get what I was trying to say though.
And FB personally I would probably pick Sif but if you pick Loki I can't argue with you. The feats support your stand more than mine.
And yes, have to agree. While AOS showings were incredibly OP compared to other Lady Sif showings. The fact the Loki fought Thor and was doing Okay puts him in front especially with his other powers.