[split] Distances between files and ranks

[Nathan Ross]

Metellus maneuvered his army to triplex acies battle array, with skirmishes between maniples, to counter the threat on the right flank.

That sounds right - and the map looks good too!

The only thing I don't get is why he brought up three lines of reserves to strengthen his flank - he'd only need two extra to form the triplex acies. Unless one of the lines was made up of skirmishers, perhaps on the extreme right? Or is there another explanation?