Just added some special movement trays to our website for Sword & Spear. This is my favorite rule set for Ancients / Medieval and Fantasy Mass battle gaming. Ideally units want to be on a single base, but I had hundreds of miniatures based on 20mm square, 25mm square, 25mm diameter, 40mm diameter, 25mm x 50mm and other size bases as a result of 35 years of playing Warhammer, Lord of the Rings and a whole host of historical game systems.
To enable all of these to be used easily, I've designed seven different movement trays / unit bases with slots to suit all of the bases mentioned above. The base also has a recess to take the orders dice, so that it stays with the unit and a slot to take a stat line.
Full details @
http://wargamesbuildings.co.uk/Sword-Spear-Movement-Trays