One of the mysteries surrounding German (i.e. Liechtenauer) and Italian (i.e. Fiore) unarmoured longsword combat (and I’m sure it keeps you awake at night too) is the different responses to a crossing at the middle of the sword (meza spada) in the two systems. At Fiore’s crossing of the swords in zogho stretto we see lots of entering with grips, pommel strikes and the like, whereas from the same starting point (swords crossed at the middles, some pressure in the contact, points threatening) Liechtenauer would have us wind, bind, or cut around (such as the twitch, zucken). My theory (and is it only a theory) is that the systems are optimised for slightly different weapons. Fiore’s longsword appears to be a little shorter than that used in the German manuscripts. (If you don't have examples to hand, you can find them at the  excellent Wiktenauer.)

It is is difficult to establish the size of the weapons from the illustrations in the manuals, but fortunately one Italian master, Filippo Vadi, explicitly determines the proportions of the sword in Chapter 2 of his De Arte Gladiatoria Dimicandi (Folio 4)

La spada vole avere iusta misura
Vole arivare el pomo sotto el brazio
Come qui apare nella mia scriptura.

The sword should be of the just measure,
The pommel should come under the arm
As it appears here in my writing.

(Translation here and below mine, from my forthcoming Veni VADI Vici)

Using Vadi's stated proportions, my sword should be 133cm (my floor-armpit measurement). If we measure the illustrations, we find that the longest sword (relative to the man holding it) is 1.31:1. I am 175cm tall: keeping this ratio, my sword should be 133.6cm long, and my floor-armpit measurement is 133cm. Pretty close: but this is the longest sword in the sample. In contrast, the swords in Fiore appear to be a bit shorter. (There is no hard evidence for this.)

In Vadi’s explanatory chapters on the art of the sword, he makes several references to techniques that re clearly Fiorean, but also many to techniques that appear to be very similar to Liechtenauer. For instance, he describes at length the way to play at the meza spada, and includes the following:

On folio 11V
Ragion de giocho de spada. Capitolo XI
Principle of the play of the sword, chapter XI

Qvando tu sei amezza spada gionto.
Facendo tu el diritto o voi el riverso.
Farai che piglie el verso.
Di quel chio dico poi che sei al ponto.

When you are joined at the half sword,
Make a mandritto or roverso,
Be sure to grasp the sense
Of what I say, because it is to the point.

Si tuui steggie tien pur lochio pronto
Et fa la uista brive con coverta.
Et tien la spada erta.
Che sopra el capo tuo le braccie gioche.

If you are there, keep a sharp eye out,
And look quickly with the cover,
And hold the sword up,
So your arms play above your head.

So when crossed at the meza spada, we leave the crossing to strike. Lifting your hands up at this point seems to indicate exactly the kind of winding action we see in the Liechtenauer material.
We can even feint on one side and strike on the other:

On folio 12V

Ragion de mezza spada.. C. XIII
Ordering the half-sword.

Essendo tu pur gionto ameza spada
Tu po bem piu et piu volte martelare
Da un sol lato trare
Da laltra parte le tue viste vada.

Being then joined at the half sword,
You can well hammer more and more times,
Striking on only one side,
Your feints go on the other side.

The problem is of course that all this is being done in circumstances where as Fioreans, we would only enter because the leave the crossing would mean being immediately struck (the defining feature of zogho stretto). But here’s the thing: with the longer swords, the situation is different. The extra length, only a few inches at most, nonetheless changes the game completely. To illustrate this I shot a short video with my student Ilpo Luhtala. The swords we used for the Fiorean crossing were an Arms and Armor Fechterspiele, at 123cm (48 1/2”) and a 117cm (46”) Pavel Moc Embleton (old version, the new ones are longer). We then switched to longer swords, about the right length for Vadi: a Peter Regenyi fechterspiele at 135cm (53”) and an Angus Trim sharp at 130cm (51”). As you can see in the video, with the shorter swords, crossed at the meza spada in measure to strike without stepping, it is easy to enter in, and very dangerous to leave the crossing, even for an instant. The points are very close to our faces. With the slightly longer swords (about 10-12% longer), the game changes completely, and there is time to safely cut around, provided you make a small motion, a “turn of the knot”:

El mzzo tempo est solo uno suoltare
De nodo: presto et subito alferrire
E raro po falire
Quando le fatto con bona mesura

The half time is just one turn
Of the knot: quick and immediately striking,
It can rarely fail
When it is done in good measure.

And we must close the line and strike with a single motion, as Vadi demands:

De tucta larte questo sie el givello
Perche inun tracto el ferrissi et para
O quanto e coxa cara
A praticarlo con bona ragione
E facte portar de larte el gonfalone.

Of all the art this is the jewel,
Because it treats as one the strike and the parry,
Oh what a valuable thing,
So practice it with good reason,
And it will let you carry the banner of the art.