The history of costume is a specialised study. The writer is not equipped to answer your questions on specific aspects of Welsh costume over the ages but it has been observed that styles in Wales generally followed those of England - although poor communications ensured a delay in the adoption of new fashions.
The accompanying Welsh archer is to be found in a 13th. century manuscript . He wears a simple tunic with a cloak in thin material over his shoulders and appears to have removed a shoe to aid his grip on the greensward. One must assume that his strange hairstyle and miniature bow illustrate the limitations of the artist!
At the end of the 12th. century Giraldus Cambrensis (Gerald of Wales) had described Welsh soldiers thus: "They are lightly armed so that their agility might not be impeded; they are clad in haubergeons (short garments of chain mail), have a handful of arrows, long lances, helmets and shields, but rarely appear with iron greaves (leg armour) ... Those of the foot-soldiers who have not bare feet, wear shoes made of raw hide, sewn up in a barbarous fashion."
Giraldus goes on to say that "The people of Gwentland (south east Wales) are more accustomed to war, more famous for valour, and more expert in archery than those in any other part of Wales". He describes the Welsh bow as being made of wild elm "rude and uncouth, but strong" and tells how arrows shot in an attack on Abergavenny Castle had "penetrated an oaken gate which was four fingers thick : in memory of which deed the arrows are still preserved sticking in the gate, with their iron piles seen on the other side".