Greetings! I have good news.
I have discovered what the first three "Unknown Values" in Unit Formation Data in FFTA's AIO editor are:
The First value is the unit's X position with horizontal position being: Byte1 value = X
The Second value is the unit's Y position with vertical position being: Byte2 value = Y
This is with the upper-rightmost part of the map being "up" (Y coordinate equals 0), and the upper-leftmost part of the map being "left" (X coordinate equals 0).
The third value is the unit's orientation: 0 = Down, 1 = Left, 2 = Up, 3 = Right.
All of this is overridden by mission events (The little cutscenes before or during a battle), so at the moment you can only change the position of units which are not programmed to have a little "walking" animation at the beginning of the battle (as seen in "Herb Hunting")
Hopefully this information is useful and finds inclusion in the eventual 0.8 release of the AIO editor.