I like Greyhawk for the reasons you mention.
For what it's worth (just about nothing!), my Greyhawk is slightly different.
-- My Yeomanry is a republic, so no knights.
-- My Keep on the Borderlands is in Bissel, where my campaign is centered. It and Ratik seem particularly good "Clash of Civilization" borderlands. In my campaign background (my group has several military history buffs) I compare Bissel to Alsace-Lorraine, the Fulda Gap, and Yugoslavia, all classic borderlands.
In my game, Bissel is closer to the 1983 Boxed Set version than From The Ashes and later published versions. Because the PC's defeated the G123D123Q1 threat, Geoff and Sterich never fell, and Bissel wasn't overrun when Ket invade it (in the 1983 book, Gygax went on about the large professional force Bissel had).
My Bissel is a border region between:
- the Baklunish civilization to the west (Ket invaded Bissel, the causus belli being a group of PC's taking Daoud's Wondrous Lanthorn from the Lost Caverns of Tsojcanth for Bissel)
- the Flannae-centric, Swiss-like civilization of Perrenland (neutral but supplying mercenaries to Ket)
- the Suloise-centric, Keoland-led Sheldomar Valley (allied with Bissel)
- the Oeridian-centric, Great Kingdom-heritage, Furyondy-led Old Ferrond region (allied with Bissel, battling Iuz)
- the elves of the Highfolk (neutral in the Bissel-Ket war because their mercenaries won't fight Perrenlanders, at war with Iuz)
Bissel is drawing in mercenaries from near and far, and has units from Gran March (still a possession of Keoland in my game) and limited heavy cavalry support from Veluna. That's because both Keoland and Furyondy-Veluna support Bissel against Ket, and because their aware of a "secret" alliance between Ket and Iuz. But Furyondy has its own problems fighting Iuz on Lake Whyestil and across the Veng River border.
(Note: I like some of the conflicts of the Greyhawk Wars, but I think they were poorly done. It makes no sense to me that Iuz would capture a strip of northern Furyondy, but not manage to push further south. So I have him in the Vesve (N & E), conquered the Horned Society, Bandit Kingdoms, and most of the Shield Lands, messing with Tenh, Rovers, and Wolf Nomads, but not in Furyondy proper, yet.)
As for patrols, local knights with followers are sometimes seen, doing their feudal duty.
-- A knight would be just as you described, though likely with plate mail.
-- The followers could be anything from just spears and javelins (Commoner 1, village militia) to studded leather with a mix of crossbows, polearms, and long swords for weapons and shields like you describe if appropriate for their weaponry (War 1 full-time troops). Rarely, they are even richer than that.
The professional soldiers of the Border Companies have excellent equipment: -- everyone has banded armor (Roman lorica segmenta) with tabards showing the symbol of Bissel and a Roman numeral for the number of their Company, longswords, daggers, and one of the following equipment combos depending on role:
-- light warhorse with heavy wooden shield (shield-shaped with Bissel's symbol) and light crossbow (mounted scouts in the vanguard or operating independently)
-- light warhorse with heavy wooden shield and lance (medium cavalry)
-- heavy wooden shield and spear (the bulk of the Border Companies, these sword infantry carry a spear as a one-shot missile weapon, like Roman infantry, except the sword is the primary weapon)
-- longbow (archers, 2nd largest force)
-- fauchard-fork or halberd (heavy infantry, mostly to defend the archers)
-- The privates would be War1, the corporals War2 or F1, sergeants War2-3, officers F2 or War 3 or higher. Most would be human males, but perhaps 30% are female, and perhaps 20% non-human, mostly half-elves and half-orcs (your natural move needs to be 30 ft so you don't slow the Company down).
-- Ranger scout units (operating separately from the Border Company main forces) would likely have chainshirts, longbows, and longswords. They might be mounted, and might have demihumans and spellcasters with them.
So the level of equipment in my Greyhawk is slightly richer/less Dark Ages than yours. Or maybe it's just that Bissel's Border Companies are pretty darn good.
