Oh. That's interesting. I've figured out what determines what crystals are in a sector, if anyone cares. Divide the map with vertical lines into three sections. One line is between SC07 and SC08. The other is between SC06 and SC09/SC01. The left section drops Earth and Ice, the middle section drops Wind and Lightning, and the right section drops Fire and Water.

This theory makes the groupings as follows:
Earth and Ice: SC03, SC06, SC11, SC13, SC14, SC15, SC19
Wind and Lightning: SC01, SC05, SC08, SC09, SC20
Water and Fire: SC02, SC04, SC07, SC10, SC12, SC16, SC17, SC22
On the border between Wind/Lightning and Water/Fire: SC18, SC21 (logic would put them with the Wind and Lightning group for balance, but it's unclear)

Recorded results in the spreadsheet:

Earth: SC02[01] SC03[16] SC06[20] SC11[15] SC13[11] SC14[06] SC15[02]
Ice: SC03[13] SC06[15] SC11[20] SC13[06] SC14[05] SC15[02]

Wind: SC01[37] SC05[41] SC08[29] SC09[14] SC10[01] SC11[01]
Lightning: SC01[24] SC05[28] SC08[25] SC09[09]

Fire: SC02[35] SC04[24] SC07[34] SC10[20] SC12[04] SC16[01]
Water: SC02[29] SC04[21] SC06[01] SC07[29] SC10[22] SC12[08] SC16[02]

Dropping the one-off outliers (marked in red) as typos, this results in:

Earth/Ice: SC03, SC06, SC11, SC13, SC14, SC15
Wind/Lightning: SC01, SC05, SC08, SC09
Fire/Water: SC02, SC04, SC07, SC10, SC12, SC16

Perfect match from SC01 to SC16. That implies what SC17-SC22 will drop, excluding SC18 and SC21 which lie on the border.


Now, if only that discovery actually mattered for something...