Does anyone use these preset formations?

[Slaists]

The trick is to do the locked group, they keep their positions relative to each other.

yes, but while you're dragging them out in a line you cannot use locked group. you have to lock it after the dragging out part. the auto-reshuffling for me happens during the dragging out part.

in other words if H stands for hastati and P for principes and you make a selection of

H-P-H-P-H-P

and then drag this out to get a smooth line, it would get auto-reshuffled into

H-H-H-P-P-P

Anyway, the point is moot for RTW 2. Here we can use the double/triple axis presets.