I have previously tried to explain to you what this means. I suspect you will ignore me, but if I have explained it to you, you cannot later deny you have not been told.
1) mixed DNA means that the DNA extract contains DNA from two or more people.
It does not mean that the DNA was from a source that contained a mixture of DNA. Two of the 'mixed DNA' results were from the basin and the bidet in the bathroom. Rep 137 and 66. Now look at the video of their collection.
http://themurderofmeredithkercher.com/Videos/police_video_november_3_2007_part2.mp4 about 1 min 50 and 3 min 50.
Note how Steffanoni swabs the bowl of the basin then the rim with the same swab. The DNA from Kercher and Knox may have been completely separate, one on the rim and one in the bowl. The same is true if you look at the swab of the bidet, the swab was wiped around the drain then around the rim. There is no way one can know the location of the DNA within the extent of the wiping. One definitely cannot say that the DNA of Knox and Kercher was co-located.
Also note how Steffanoni holds the swabs in her gloved hands. Note the folds of the gloves across the back of her hand and at the wrist. She does not change gloves between samples. She could have transferred DNA from one swab / site to another. Also note how she uses metal (non disposable) tweezers for picking the hair out of the basin.
As Steffanoni says herself. Even assuming the DNA is co-located, one cannot determine the order or time of deposition. Mixed DNA does not mean mingled DNA. More likely is layered. There could be DNA of person A from epithelials (an excellent source of DNA) then a drop of blood on top. Or vice versa. Mouth epithelials are an excellent source of DNA. My guess is the DNA from the basin will be epithelials from the mouth from teeth brushing.
So I am afraid this obsession you have with how the blood has to be wet is just a misunderstanding of what is meant by mixed DNA. It is mixed in the extract, it does not mean the DNA was mingled in one spot prior to being collected.