Each of my characters have different preferences when they lead the army/armies as General/Marshal/Vice Marshal. But overall here's my playstyle.
Speaking from Strategy
(A) Knowing your lands geography better than your enemies
Good for defensive play. For example, Perdan armies under Atanamir have a bigger CS force and more Infantry than Nivemus armies combined. When you are outnumbered by enemy in terms of these factors, the best you can do is play defensive strategy. This was one of the two times I outsmarted Atanamir with this strategy. I call it as the Salta trap door strategy. When Perdan elite army sitting at Gadlock driving it rogue, our realm morale was at its low moment. My character Brock decided to order his army to make 2 turns move from Oberndorf to Gadlock. We not going to sit back at Oberndorf and play staring match with Perdan army at Gadlock. Then we have some allied armies from Sirion and Eponllyn placed at Salta as late as possible along with a few of our nobles. The allies late movement to Salta would caught Atanamir off guard. As predicted, Atanamir decided to move from Gadlock to Salta, as I know Nivemus local lands very well, Gadlock to Salta travel time is 2-3 turns move. So half Perdan army was caught at battle at Salta arriving too early, another half army had to keep turn around many times between Salta and Gadlock, where Nivemus armies already reached Gadlock. Thus the trapdoor strategy was sprung up where we can place 2 almost evenly matched CS allied armies at both end of 2 regions, making the enemy stuck on the road travels trying to preserve their armies. Having Perdan armies keep moving back and forth between Salta and Gadlock with no end in sight for them to turn around anymore, they decided to face battles where they are now outnumbered. This strategy is what Lapallanch calls "forcing his enemies to react to his actions".
Another time when you see the enemy retreating from their failed assault on your capital city. Separate your armies and allied armies into two armies and move them into 2 regions where enemy would retreat next. Block them at their possible escape route, kill and destroy their Captain and long time units, with local lands Geography and any militia raised by your region lords, all these factors together can swing the battlefields.
(B) Misdirection
I am used to command army outnumbered CS by the enemy countless times. Not a surprise thing when I often joined realms that have lower military CS. In battles, if you know how to make CS do not count, that would be better. When enemy has bigger CS next door region adjacent to my position, while I waiting for my reinforcement to arrive to even the fight, I ordered misdirection to one of precious targets to the enemy. When enemy fall for the misdirection trick, we can move in for a mopping up. Also when no precious target available, we pretend to retreat but route the enemy with reinforcement from a region that is out of enemy view. That would be a bad enemy movement since they do not have scout on possible reinforcement. See point E below where the counter strategy is.
(C) Spy
Banish your own noble, send spy undercover to enemy realm. When enemy suspect there is a spy in their camp and enemy decide to give a false order, I co-operate by reacting to that false order. Give your spy some credibility. For example, spy give me all enemy armies CS information. Do not share with too many people the information. Otherwise get friendly with people outside your realm. Talk with them more, share a little bit of yourself whenever possible. "Sharing is caring" strategy as I call it, this will make all players appreciate being part of the actions even if behind the scene.
(D) Looting
I aim to loot for gold and food, pillage and maraud. Reduce the enemy capability and make the enemy worry about themselves. On some occasions, I would loot and run away from the regions to avoid the peasants. No points educating the peasants who holding pitch forks and shovels high above their heads ready to swing on you, isn't it?
(E) Scout
Send a unitless noble or nobles with unit to scout, an infiltrator to wound their nobles before the big battles. Of course when the infiltrator was caught, prepare an alibi and pretend to disown the infiltrator. Then have the infiltrator come back into service. Also if you have spy as Scout as in point C above, all the better. That is how I know enemy military build up before it all happens, so that I can muster the armies and hit them before they gather together.
(F) Formations
Successful armies often depend on good formation settings that utilize the mix of the units the nobles field. When you have more Infantry than enemy, rushing headlong into the enemies and engage them in melee attacks early on with Infantry Charge formation. Of course if your armies have good range units, try Infantry Wall or place the range units further back with melee units close by.
(G) Identify chokepoint
Identify the defensive chokepoint in your realm as early as possible. You cannot always stay offensive all the time, be ready when your armies got destroyed. For example, Iglavik is a Mountainland with a Palisade wall and a good chokepoint for Oritolon realm. My character who is the region lord who is conducting homeland duty fighting against monsters and undead, she saved a lot of gold fund, let us call it as emergency war fund and place a lot of mix of Infantry and Archer militia at last minute to defend it against the combined attacks of 2 realms successfully.