nullspace

In this hand Dummy (north) C K 3 2 D K J 10 9 H 3 2 S 5 4 3 2 Declarer C A Q J 10 9 D A Q 2 H S A J 10 9 8 Contract is 6S (lead is hearts) According to the software line of play after ruffing the first hearts, cross to dummy diamonds, finesse spades. If fail, ruff the hearts return and cross to dummy clubs, finesse again. What i do not understand is that since the contract have a 9 card fit, why not cash Ace first (catches K/Q singleton 24.8%) and if fail lead J (40.7% there is a 2-2 break). In the software line of play, they are guessing East have 3 Spades (24.8%) and risk a void in either dimes or clubs (5.4%). Which play will you guys find superior to the other?