Kostner had some great SPs, but Cohen also had iconic SPs that matched or exceed Kostner's SPs. Her best ones were phenomenal and would definitely NOT all be in the same 6-10 range when stacked up against Kostner's:
Dark Eyes
Malaguena
My Sweet and Tender Beast
I personally prefer all three of the above SPs to Kostner's Ave Maria.
Plus, in terms of LPs, Cohen's Romeo and Juliet LP stacks up to Faun, Mozart and Bolero.
I don't know about you, but Ava Maria has more intricacy and difficulty than all 3 SPs combined. If you stack them up back to back, I don't know anyone but Sasha's parents would rank them higher. Figure skating is still a sport, correct? Under what universe would any of Sasha's SPs place higher than Ava Maria?