Seeking suggestions for Roman vs. Celt or German dio 1/72
A few years ago I made a dio of Imperial legionaries vs British Celts during Boudicca's revolt in 1/72 scale. It was an ambush scene where a column of Roman infantry are attacked by Celts. It came out quite nice and it was the first time I used shading and highlighting on figures.
For my next dio I'd like to display a Roman century in formation versus Celtic or German warriors and cavalry.
I'm seeking information on how a century was formed for battle in 1st and 2nd Cent. AD. I know the legion was formed in a checkerboard fashion, but I've also read that against most opponents they would not have had gaps between centuries. Gaps between units may have been advantageous against an opponent in phalanx formation, but against a barbarian mob it would not have been. I've also read that Romans would loose a volley of pilums at their enemy and then engage with swords (gladius), and that the small swinging radius of the gladius allowed them to fight close together.
Are there any good reference books or websites that deal with Roman infantry formations and tactics in the 1st and 2nd Cent. AD? (early to mid Imperial period).
Thank you,
Dave