When it is written : "no more than 1" laterally", does it means parallel ?
If not, does all the bases in the flank zone to be at 1" or less ?
If not, could you have a curved line of battle, with three units with the second at 45° and the third 45° from the previous so 90° from the first one ?
IMHO, the strict parallel option generated very beautiful battle line with a tactical interest with large units between being in line of battle or oriented with an angle to charge flank after, but out of the line, because not parallel.
A lot of talks about this rules clarification as a video on the net showen a non-linear line of battle !