An article regarding Legionary Guardsman or Lanciarius, hopefully it helps your team.
http://lukeuedasarson.com/Lanciarii.html
I found this part useful for your team:
The first instance of a soldier termed a lanciarius in Latin seems to come from the gravestone of Aurelius Mucianus, a soldier from Legio II Parthica, where he is described as a 'Discens Lanchiari(....)' on his headstone in Apamea dated to the early 3rd century AD, ie. a "trainee lanciarius". This man's tombstone is illustrated in J.C.Balty's "Apamea in Syria in the Second and Third Centuries A.D." in the Journal of Roman Studies, 78 (1988), 91-104, along with a discussion on the dating of the gravestone. Apamea was a Greek-speaking area, hence the hybrid spelling used; and he is shown holding 5 large javelins - ie. lanceae, in his right hand, while his left hand bears a shield. The shield appears to be oval (a foreshortened round shield can not be ruled out however), with a central round boss, and its small size would well fit the light infantry hypothesis. However, it can be readily seen that the other numerous gravestones from Apamea showing (non-lanciarii) legionaries who carry shields have them depicted the same small size, so the conclusion that the size of the shield as depicted is much smaller than real-life is unavoidable, and it is in all likelyhood no different from any other legionary shield. This man's position in Legio II Parthica makes it plain that, at least at this date, lanciarii were drawn from the ranks of the legionaries; his almost unique tombstone amongst many dozens indicates that the limited numbers of lanciarii attested in Josephus and Arrian - one or two hundred in a force of many thousands, continued into the 3rd century. In addition to Mucianus, one other lanciarius, not a discens, also has a tombstone at Apamea; he is shown holding 4 lanceae.
Very recently, following discussion of an earlier draft of this article, Duncan Head made the observation that the first appearence of lanciarii in Roman armies seems to be occur around the same time as antesignani disappear from the sources. Antesignani, "those before the standards", undoubtably formed part of the standard heavy infantry line of battle in the Punic wars (eg. Livy 23.29.3), but they seem to have taken on some of the roles of the former light infantry (velites) as the 1st century BC progressed - when the velites themselves finally disappeared from the scene. Most notably in Caesar, they can be found supporting cavalry, seizing advanced positions etc. There is some evidence that they may have been more lightly equipped than other legionaries, at least some of the time, and in such roles, lanceae may have been more suitable weapons than standard pila. Perhaps this practice became codified in early empire, as did so many other aspects of the Roman military. In this case, we might well not only conclude that lanciarii were legionary light infantry, but that they were merely an old troop-type under a new name.