To clarify..ARMA is a HEMA organisation. Its just the oldest and best known. ;-)
For those who are curious about such things, the medieval and renaissance european fighting men a grappling art as fully developed as Jujutsu or Judo. When used for play it was called Ringkunst, when used in battle it was called Kampfringen which translates to Battle Grappling. Strictly speaking, Kampfringen was the art described by wrestling master Ott Jud, but we use it as catch all term to describe all the combat grappling arts of the period, such as Italian Abrazare. You wont see much ground fighting, as it was designed for throwing and joint breaks. Here are some examples of ringen.
These ones are from the best ringen group in the world, Ringschule Wroclaw
https://www.youtube.com/watch?v=tm6P1boVkY0
https://www.youtube.com/watch?v=9Ge6l_bMLcs
Depends on the italian style. Fiore's unarmoured longsword is much more closely integrated with grappling than the german school imho. Whereas the germans prefer to wind from a hard bind, Fiore liked to close and perform join locks or disarms in what he calls the Giocco Stretto, the Close play'
https://www.youtube.com/watch?v=3WCgubznOlI
Armoured sword fighting, is, of course, almost all grappling.
https://www.youtube.com/watch?v=G4k-vjdeZO4
ARMA uses the rank system derived from a 15th century English Martial arts guild, the London Masters of Defense. You join as a novice. Once you reach a certain level, you take a test called a prize playing. In the prize playing, you are made to fight all comers, until everyone is satisfied. If you acquit yourself well, you are awarded the rank of Scholar. At another point you take another prize playing for the rank of free scholar. Then again to the rank of Provost. This system and variations of it are used in many HEMA orgs in the english speaking world. (incidentally, this is where we get the term prize fight from...people liked to watch these prize playings so they started charging money to see them, and so began the sport fighting culture in the english speaking world.)