Ah, You are an adventurer, I see? You may have spotted the Cretas Monarchy, yes? What is this tiny one castle, one village kingdom on the outskirts of civilized lands?
The short answer is that they're an armor-focused and defensive collection of pike troops and shield-men, with some ancillary archers (poor damage, but better armor than average) and cavalry (fairly poor, but decent armor and shock value.)
Their one-star troop is the Cretasan Warden/Iron-Clad line, who are excellent (and wonderfully cost effective) defensive infantry with fantastic shields who make capturing castles and towns from factions with plenty of archers (like those pesky elves, or Tolranians) much, much, much easier.
... However, if you're in need of a greater challenge after your previous Perisno adventure or you just like the idea of rooting for the little guys as I do, then here's the breakdown on Cretasan Troops:
1.) You start off with (arguably) the weakest militia unit in the game, the Cretasan Rabble, (outside of the jungle-dwellers, perhaps). Cretesan rabble are barely better equipped than your average farmer, and anything stronger than a light breeze will topple them like a house of cards. Though it is rather amusing, if you have the time, to gather a decent army of rabble, charge them into a peasant/bandit group and watch them slap each other pathetically with witty insults and pathetically insufficient weaponry.
2.) The next two tiers get no better, as they have the also have some of the weakest militia (Cretasan Levy, then Cretasan Vigil) and bow militia (Cretasan Huntsmen) in the game for their next two upgrades. The sole advantage these troops possess is the reach of their spears, which allows them to provide some assistance in sieges (although if these guys are manning your walls, you got bigger problems, my friend) and that they can stop up cavalry if you get lucky (although even basic cavalry types can still mow them down like I mow down BBQ at buffalo wildwings, and cav archers rain death upon their poor, shield-less frames. Joking aside, Cretasan Vigil have solid helmets and decent armor for their class, so they make decent stop-gap troops if you're in dire need of numbers, and will at least take a few seconds for even more elite troops to hack down.
3.) However, things turn do up a bit at the next upgrade level.
Cretasan Defenders are actually solid defensive troops, armed with awlpikes. Now, of course, at the fourth upgrade, you would hope so. If you compare them to, say, Hakkon Heavy Footmen, Kaikoth Warriors, or even the slave-tier units you have already gone from Slave-> Gladiator->Veteran Gladiator->Super-Gladiator, and even those top tier gladiators will wreck defenders. But that isn't their purpose. Their awlpikes are really most useful sitting at the top of a siege wall, where multiple defenders can strike an enemy at once, or in defense of a line of archers/crossbowmen. You can give them a special group name (like 5 or 6) and position them in front of archers so that they can get work down in front of your main-line beauties.
The real beauty of Cretasan troops is the Cretasan Warden. They have stout shields, good armor, and decent health/power-strike, making for a good offensive and defensive sledgehammer. When I'm doing a Cretasan run, 3/4ths of my troops will be upgraded into Cretasan Wardens. These guys can stand up to infantry or cavalry from just about any faction and take a real beating, even when compared to Macaavian Swordmasters or Hakkon Heavy Infantry. These guys got game. They're a bit slow, and not as useful offensively as they are defensively, but they're your bread and butter for mid-tier troops.
Of course, we also have the Cretasan Skilled Huntsmen, while certainly better than ordinary huntsmen, aren't that great. They have above average armor, for an archer, but their weak bows and power draw strength make them underwhelming. Their two-handed back-up weapon is a spear, which is decent against pesky Draharan or Khannish cavalry if they're light enough, but not great if they get so much as sneezed at by any other respectable unit. Including other archers.
4.) At the fourth upgrade level, we finally have access to our first cavalry unit, the appropriately named Cretasan Cavalry. These are a decent medium-light cavalry that is useful for disrupting enemy archers like all cavalry are, but rely only on their polearms. The lack of a secondary weapon or a shield is what sinks these guys, though. Without a secondary weapon, they tend to struggle in melee, which relegates them to flank-charge-tactics. The lack of a shield makes them fairly vulnerable to Cav Archers as well, as although their horses are standard and their armor is again decent, they have a hard time chasing down fleet-footed cav archers.
Cretasan Horse-Hunters are solid troops. Their bows and power-draw are substantially improved from the previous iteration, and their silver-mail affords them good protection. In addition to this, they have an upgraded version of their spear, a poleaxe, which allows them to be useful in melee, and even more useful in sieges.
The main troops you'll want in any Cretasan army however, are the Cretasan Iron-Clads.
These guys are BOSS. These troops have high armor values, good offensive capabilities, and fantastic Black-Snake Shields. You'll want to upgrade as many troops into these as soon as you can. They make excellent battle line troops, excellent siege warriors due to their powerful shields, and even make for surprisingly good cavalry killers in addition to a small number of Cretasan Custodians (the upgraded defender line, same as the previous, but somewhat stronger overall) is that they also can bring down cavalry). The main reason you want these troops though is that they're cheap. They're a fully upgraded troop, capable of bringing down enemy elites, and they don't require an extra upgrade! This is the true strength of the Cretasan Monarchy. They're extremely cost efficient to field, and much quicker to replace. Having a few followers with a decent train-skill can upgrade 100 rabble into 100 iron-clad in just a few days. The primary downfall of most elite troops is that they're impossibly expensive, yes, but even when you have the money it just takes too gosh-darn long to train them.
5.) The final tier of Cretasan Monarchy troops is the Eidolon tier, Cretesan Eidolon (infantry) and Cretasan Eidolon Knights. Of course, as final-tier elites, these troops pack a punch. Sadly, their relatively weak weapons make it hard for them to compare to the elite troops of other factions, even though they are well armored. The infantry version makes for a superior Cretasan Custodian, in their use of a polearm, and the Eidolon Knights are powerful, yes, but not in comparison to say, Draharan Royal Cavalry, or the Reich's Drachenritters.
You'll want a majority of your troops to be Iron-Clads, they're just much more efficient troops than the rest of your arsenal. However, in support of your main-heavy infantry line, you'll want a good number of Horse-Hunters, preferably far enough away on some other rise that they're not targeted, and preferably defended from assault by any Vigils or Defenders in your army.
You can back up the Iron-Clads with some Eidolon infantry, to help deal with any cavalry charges. Your own cavalry is still useful for charging archers and the rear of their infantry as battle lines meet, but should be carefully managed to use them to full effectiveness.
Set up on a hill, with your cav nearby, and wait for the enemy to come to you. If they have more missile-power than you, then you can tell your Iron-Clads to advance under the cover of your archer fire, but their shields are so good that you can let arrows rain on you disproportionately and still come out ahead. Then tell your Iron-Clad line to advance, or set them against the enemy cav-charge so that your pole-arm troops can cut them up for you.
Cav archers are annoying but don't threaten your iron-clads much. The real trick is catching them and keeping them away from your units without shields. Your Eidolon Knights are the best candidates for this, but it's hard to aquire a lot of them. Thankfully your pole-arms do a fairly good job of keeping cavalry in place for your ironclads to smash, as long as you aren't too outnumbered.
Enjoy you crazy souls.