Are there any groups other than the British Ludus Gladiatorius that have published some substantial pieces of research on gladiatorial fighting techniques and the stage-fighting "numbers" taught to the ancient gladiators? I'm not looking for only the most accurate and scientifically rigorous sort of information, just plausible (and detailed) opinions that may illuminate one aspect or another about the techniques of gladiatorial combat.

Thanks beforehand![/url]

For two years ago we solved this problem. There are many books about gladiators in english but for my was importent one book (original in holland and translated in czech, i mean in english you can buy):
Meijer, Fik: Gladiatoren. Athenaeum-Polak, Van Gnnep. Amsterdam 2004. In this book is translated the methods of drill for legionars (Vegetius), other contemporary perception in antik literatur and pictures of archaelogy. We have very good bases in medieval sword and shield fencing therefore we only stadied mosaik scravls tomb stone (I was in Roma, Villa Borgheze). We had found out, it is very similar as medieval fight and you can see in:
Marozzo, Achile: Opera Nova. Mutinae 1536. There you can learn basis (stance, work with schield and sword).
I suggest you learn methods of legionars drill (Vegetius, Strategikon), observe every picture of gladiators, Marozzo (bases but other is your iventions), more exercise gladius is short you must with shield more body moving (forg and net use my friend). Last fact is: gladiators had to enjoy and in Amphitheatere is distance to viewer 100-300 metr, fight was very difficult to learn (you don´t need bond on oposite, you must make great moving). We try see our fight from distance and we must see what happens.
I mean there are more way to gladiators but I don´t no how made it others.