I vey interested to see similarities between some of the technique and strategies of medieval wrestling and those of Ryōi Shintō-ryū Jūjutsu (良移心当流 柔術).

I recently bought a copy of Medieval Wrestling - Modern Practice of a Fifteenth Century Art by Jessica Finley (2014)

When one examines the medieval heavy armour seen in European museums and stately homes it is probably jousting armour rather than battlefield armour. Battlefield armour by necessity would have had to be considerably lighter.

So, although different in design, the weight and movement potential of European and Japanese armoured fighters may have been similar..

As such the grappling of medieval Europe and kumiuchi (and later Jūjutsu) of Japan both developed under similar conditions of combat.

I can see similarities between the technique an the top right and one that is described in the 'Ryōi Shintō-ryū - Tan Mei Mokuroku' (鍛名目録):

“The enemy grabs your belt with both hands and drives in, hit him with your elbow.”.

The technique on the bottom right is very similar to ‘Shide’ (四手- 4 hands) position from the Ryōi Shintō-ryū - Yawara e kumi-dai (柔え組大), - where both combatants engage together in a close double handed grip.