Medieval: Total War/Fortress level units

Lancers
A Spanish exclusive heavy cavalry at fortress level with a Master Armourer, Master Spearmaker and Master Horse Breeders Guild. They are extremely powerful units recommended for charging straight into enemy lines.. watch any spearmen under halbedier level fall like dominoes under their long pointy lances. They are even more powerful when flanking.

Janissary Units
There are 3 Janissary Units. They all have in Comon, that they are exclusive Units of the Turkish and that they need a Military Academie who itselfs requiers a Great Mosque. Since the Great Mosque can only be buitd once in your Kindom, these Units are somewhat sparse. You can bypass this limit by tearing down the Mosque after the Mititary Academie is finished and build a new great Mosque in another Province. Note, that this will take time and may be considerd Exploiting, if not cheating. The Janissary Units are:

Janissary Archer
They require an additional Master Boyer. They are slow archers whith prety normal archer Stats exept a higher Moral and the Elite and Discipline Status. They shoutdn't be used in meele combat. They are the cheapest and in most players opinon, worst Janissary Unit and you should use another unit if possible.

Janissary infantry
They require an additional Master Boyer an a Swordsmith Guild. They are slow archers whith slihtly worse Stats than Chivalric men at arms but are Elite and Disciplined. They can be used in meele combat. They are a better Version of the Janissary Archer and probably the best Archer Infantry Unit.

Janissary heavy infantry
They require an additional Master Spearmaker. They are fast infantry soliders with a Helbard which gives bonus against armour and against cavalry. They have High Moral and are Elite and Disciplined. They are the most expensive but, in most players opinon, the best Janissary Unit. If you only have one Province for Janissary Units this one is your Pick in most cases.