Actually I don't really know how to describe likeness if not at least lighting is involved... there are certain shapes can only be expressed through lighting shapes... Also I'm sort of prosopagnosia so I don't tend to recognize faces that easily

Very well done! I think you captured their likeness very well.

Hello @Jan D.,I agree,I think you get the proportion and anatomy correct,but your likeness definetly need some work.What particulary strike out to me,is that you didn't exaggarate the facial feature enough.For example,here is a John singer sargent painting,where he would make the hair fuller and the neck longer(you can read more on this on this james gurney post http://gurneyjourney.blogspot.com/2010/09/caricature-and-likeness.html) On a more extreme example,here is Naoki URasawa drawing of Stephen king,where he would make the area between the nose and mouth bigger.See also how he made the wrinkle more noticeable,exaggarating the roundness of the cheeck and the blockiness of the jaw. Though I can see a bit of likeness in the drawings on the left (I think you exaggarate the beard for the first two and the eyebrow on the bottom you would get it.)I think the drawing you miss the mark is the bottom right.Particulary how I feel the nose should be a little bit longer and the lower lips a bit fuller. I'll also think that the top right drawing need longer eyebrow and fuller lips(alongside rounder cheeckbone).and the middle right need a shorter nose and blockier cheek(though these are more subtle compare to the previous critique)I also I added some overdrawing for what my personal solution would be,if that helps. But anyway that's all I got,hopefully it was useful and not just a waste of time >_<(also please keep going,you're doing great by praticing :D)