I do not say this as a dis on Justin because he does great stuff, but I do not feel he has looked in as deeply as some others of us have. And I have had short conversations with him some on FB in the Acid group and he acknowledged my take after I went into some detail.
Really, the best way to see the divergence in them is to look at the combos. If you dig up Josh's Acid Pastel Spot and compare it to Justin's Confusion Pastel Spot and Fred's Pastel Spot Static you can see pretty clear differences. You see these same differences in the Lesser combos and the Pin combos.
Justin and Josh have taken their projects in pretty different directions so it is hard to do a one to one comparison in terms of "best" combos. Personally, I am a huge Albino fan so I think Josh has taken the superior path LOL
To date both Josh and Justin have made clutches that could have produced them and no visually distinct superform has been made. It is possible some of the "high-expression" animals from those clutches are supers but we have to wait for those animals to be bred out which has not happened yet