A strategy I am trying ...

[kiwitt]

I look to hold 3-4 core provinces, these are developed to the full.

These get the first Castle upgrades, old conquered provinces are usually one level below e.g. if core is Citadel, conquered are Castles. This gives an appearance of a central core to develop and any invading army would need to assault ever stronger castles.

At the fringes, I am trying the tactic of not building keeps, so I can hire mercenaries easily, when required.

Playing the Sicilians, currently I have Sicily, Naples and Malta all at Castle Level. I have all Britain and Ireland at Keep Level, due to an english / french rebellion and bribing the rebels. I have also Sweden and Norway at fort level, I am planning to use as bases for "mercenaries", if I need them.

As a way of encouraging mercanaries there, should I start to disband lessor troops there.

[{KotR}Lionheart]

I tend to use the opposite tactic, that is making my frontier provinces strong, making them a good base to launch further attacks, and also stopping the enemy penetrating into my 'soft economical underbelly', ie my core provinces whoich i try to mae as economically advanced as possible,with top level troop producing faciliites

[bretwalda]

None of the above. I tend to assign provinces according to their specialties and try to develop accordingly. Bonus valor troops, iron deposits, merchant bonus... Also I try not to rely on fortifications on holding a territory and try to have as few border provinces as possible...

[Odin]

I look to hold 3-4 core provinces, these are developed to the full.

These get the first Castle upgrades, old conquered provinces are usually one level below e.g. if core is Citadel, conquered are Castles. This gives an appearance of a central core to develop and any invading army would need to assault ever stronger castles.

At the fringes, I am trying the tactic of not building keeps, so I can hire mercenaries easily, when required.

Playing the Sicilians, currently I have Sicily, Naples and Malta all at Castle Level. I have all Britain and Ireland at Keep Level, due to an english / french rebellion and bribing the rebels. I have also Sweden and Norway at fort level, I am planning to use as bases for "mercenaries", if I need them.

As a way of encouraging mercanaries there, should I start to disband lessor troops there.

Based on what you have by way of territory already you must be rich. So if you have the cash why disband anything? and why not build up all your provinces?

I understand your theory here, but if you have the cash its sort of moot. Personally I am in the camp of bretwalda and keep provinces specific to thier strengths. Good concept regarding an inner defence core, but that wouldnt be my primary reason for building up to Citadel, for me its all about getting the best units in the appropriate province.

Again, it all comes down to Florins, if you got em, spend them !

[CherryDanish]

It also depends on what faction you're playing as well. While I feel it's best to assign provinces roles based on resources and tech trees (ie: if a province is higher up on the tech tree but doesn't have iron, screw it, I'm still building advanced troops here if I can) my strategy varies depending on faction.

For instance, as a muslim faction, the fastest way to score quick wins is to go absolutely psycho once you have a financial base and send an army out to smoke your top 3 enemies/rivals. Don't bring siege equipment, you won't need it. Hit your target one province at a time and move on to the next one, next round. Meantime, build 2-3 Jihads for every enemy province and zerg the hell out of them. With this tactic you can reasonably take HUGE parts of the map in 10-20 year timeframes. Your ruler becomes massively pious in the process (which helps keep order) and their influence becomes insane.

With Christians I tend to use a more methodical approach and go quality over quantity, but I crusade when my faction allows me in the earlier portion of the game to secure quality cav that's not usually available to me till later.

Non crusading christian factions I use assassins more and rely more strongly on tactics over strategy.