I thought this was interesting --> Medium Foot or Heavy Foot
It corrects my misunderstanding of the differences between them.
Medium Foot
Thureophoroi
Roman auxiliaries
Once again, we allow players to choose their own interpretation of the evidence - but not to have their cake and eat it as a tournament play optimization ploy.
It corrects my misunderstanding of the differences between them.
Medium Foot
Medium Foot in FoG do not represent some sort of dual role battle line/skirmishing troops. (You will notice that the rules don't allow them to skirmish). They are battle line troops whose fighting style makes them less dependent on maintaining a rigid formation at all times than those types classified as Heavy Foot. Hence they can move somewhat faster than HF, are less affected by adverse terrain, but are more vulnerable to a cavalry charge. (Roman Legionaries are something of a grey area in this regard - we ultimately plumped for classifying them as HF, though arguably they could have been classified as MF. However, we felt this would make them too vulnerable against cavalry, so we classified them as HF and dealt with the greater need of spears and pikes for rigid formation using the POAs).
Thureophoroi
It is not so much a question of them choosing to operate as heavy or medium foot on different occasions, it is more a question of interpretation of whether their battle line formation should be classified as HF or MF. As we are uncertain as to how their battle line formation should best be classified we allow players to make up their own minds.
We accept Luke Ueda-Sarsen's interpretation of the evidence - they could either operate as battle line spearmen, or as javelin skirmishers. In the latter role (as Euzonoi) they would be classified as LF Javelins. They did not operate in both modes in the same battle.
The HF/MF classification is to represent their battle line formation only, not their alternative skirmishing role. Hence there is no justification for allowing a player to switch between the two in the course of a tournament.
There would be justification in allowing them to switch between HF/MF and LF in different battles, but to avoid complication the lists do not allow that.
Roman auxiliaries
In the case of Roman auxiliaries the argument is much the same. The question is whether their historical role is best represented by HF or MF. There is absolutely no suggestion or intention that they should be able to switch between the two on different occasions.
Once again, we allow players to choose their own interpretation of the evidence - but not to have their cake and eat it as a tournament play optimization ploy.