English tactics don’t match central European tactics.
The English archers were a central part of their army. Archers in the rest of Europe were supporting troops for skirmishing at the beginning of a battle or special tactics (or of course castle defense) with the mounted knights fighting in melee combat.
Beyond that the Englishmen at Agincourt had to fight against vastly superior forces (by numbers) so they couldn’t afford to split up their army in ranged and melee parts. To actually being able to overcome the superior forces of the Frenchmen they had to use their clever ranged+melee tactics which was both, an affront against the French coduct of chivalry and a new tactics not known before on the European mainland. It’s very unlikely that troops in Bohemia at 1400 used English tactics and warfare on a greater scale. Too deep was their cultural dependence from Germany and France with its chivalric values and traditional combat tactics.
But I agree on your statement that bow quivers were useful for mounted archers with smaller and curved bows originated in the Middle East (which the crusaders brought back in the centuries before) while it wasn’t very practical for longbows anyway.