Some examples: for a 53s fight, with 2.6904 attacks per second, 50.5 CC, 19 APoC, and just casting WW I get an average of 4120 WW tics over the duration of the fight. For reference, that APS means 33 tics per cast, or about 14 WW active at a time, on average. 4120 tics means about 2060 crits which means about 260 SA procs, which is what my model is calculating.
My dps data for my 53s Ghom fight (my dps is really low because I swap to a 20 dps weapon for Hell (10) data collection:
Char sheet dps = 16589.47
Effective Weapon Damage = Char sheet dps / APS = 6166.17
Effective DPS with Storm Armor: 44791.55
Effective DPS with Storm Armor and SA: 71295.53
Approximate dps of SA = 26503.99
Total SA damage = SA DPS * 53s = 1391459
SA Damage per proc = Effective Weapon Damage * 0.35 = 2158.16
Total SA procs = SA damage / SA damage per proc = 645
Are you sure SA damage is based on effective weapon dps (i.e., not including APS) ? Maybe it's based on char sheet dps, which includes APS. In that case,
# SA procs = 645 / 2.6904 = 240
which is closer to the 260 that you seem to be expecting.