The research work we do has many tools and in order to better understand our "study objects" we need to try to use as many of them as possible. Here are some of them.
1. Studies in Medieval and Renaissance History.
a. Studies in Language History.
b. Studies in Art History and its development (perspective etc).
c. Studies of development of Society.
d. Studies of other artwork that depict the same or similar positions and techniques described in the Fight books.
e. Studies of Combat Archaeology.
f. Studies of the development of arms and armour.
g. Studies of historical garments and manufacture.
h. Research into the lives of the fencing masters, authors and fencing guilds.
2. Comparative studies of techniques with the same name, described by different authors of manuals from ca 1280-1672.
3. Detail studies of images that depict the techniques above.
4. Studies of body mechanics.
5. Practical application in full contact and speed and few, changing rules to counter the natural tendecy to use the rules to one's advantage.
6. Test cutting with sharp weapons.
7. Comparative studies with other martial arts traditions.
Studies can be executed both as reading of other research material, individual and group studies of original source material, in debate with other researchers and in applied form of training/sparring where the techniques are analyzed.
My personal opinion is that it is the principles behind the fighting arts that is the most important, and not the techniques themselves, since the techniques are a kind of embodiment of the principles. If you have understood the principles and can use them, then the techniques come naturally. In the case of Liechtenauer it involves principles like the principle of leverage, weak against strong, soft against hard, distance management, timing, taking/retaking the initiative and tactile sensitivity in the "bind".
All this applies to all weapons and all techniques are based on these in one way or the other. This is why I think it is possible to recreate the fighting arts very well, even if several techniques are unclear, as long as one has understood the principles. Sports like tennis and boxing work in the same way. The movements are defined differently, but have to constantly be adapted to the situation. There are better and worse ways to punch, but they all depend on the same principles, even if they are performed a bit differently.