Just put 1x10 on my Soul - measured up chain using the "two biggest rings plus 2" method, joined up the chain, and the derailleur nearly ties itself in a knot in the 36t ring. Had to add back in two links, and it's still quite tight. I used the exact same method on my Spicy, and it worked perfectly.
Why? Same method, and identical parts (other than an E13 LS1 on the Soul and an MRP Lopes on the Spicy) - SRAM X9 Short Cage, XT 11-36 Cass, 34t ring on both.