The Sync Cursor Action syncs the mouse cursor positioning based on pixel location for a given window. With your chosen videofx layout style, then the mouse cursor would be placed at the exact same pixel location for each window. If the toons are facing slightly different directions, and/or have different camera angles, then this does mean, in game, the cursor position is not on the exact same spot in game, and if the main is facing another direction (like a 180), then where your main is aiming, is going to be completely different.
Usually if dragging a bunch of toons on follow, and using a SetView macro, the sync cursor action to target a location, it is fairly close to where your main is targeting, but not exact, as your follow toons are a couple of steps behind your main, so their target position is slightly behind for the same pixel location of the mouse. Same deal if they happen to be facing slightly to the left/right of your main.
So, the question really becomes, is the sync cursor action not putting the cursor in the same pixel location per game window?.
/e
Also recommendations indicate your macro should be
- Code:
/cast [@cursor]Blizzard
Note the lack of space between the modifier and the start of the spell name