I have just finished my Poland long campaign. It was fun... as always :)

My east border was at Halych, Vilnus, Smolensk and Iasi, the west border was at Hamburg, Magdeburg and Norymberg. All those were castles (i changed Norymberg to a castle). South i went to Constantinopole. I waited for the Mongols and forced them to fight Turks and Egipt so only few stacks that went thorugh Russia i had to fight personally.

After they were gone i pushed through to the Holy Land. I was done before the Timurids arrive.

In the north i conquered Danemark. The HRE was left as a minor noation between me and the French. I've only kept great relations with them and the Pope. In the south was my main battle front so i did not have a constant south border,just used the castles that i gained for troop reproduction.

My patrol army was made out of a general 6x polish noble, 2x strzelcy. I had several of them. They dispatched the rebels quickly and without any trouble.
Border castle garrisons included. 4x lithuanian archers, 2x woodsmen, 4x spearmen, 2x DPK, and some artillery usually ballista or ribault or serpentine which i placed in a central possition to the gate so when the enemies charged the units on the sides i usually rooted them with a quick headshot :)
The main hammer was a all cavalry army with some minor exceptions whene i had to take a castle eraly.
The army was made out of 6x Polish Guard, 4x Polish Nobles, 2x Strzelcy, 2x Lithuanian cavalry, 1-2 General, 4x Hussars. I can defeat any stack with this army, in the singleplayer ofcourse. :)