It's a question of time. I want them to gather, and go to my target (a siege, or a weaker lord wandering and too slow). If I summon them while in my castle, do they go to that castle first? Or does the AI just direct them towards me?
When I summon a war party, do lords go to that location or directly to me
mount-and-blade
Related Solutions
One trick I used to use (for non-seige engine attacks) is to load up on good archers, and organize them top of the list. I also had several NPCs with good medical skills etc that help convert "deaths" to "injuries". You also need pretty good morale going in.
Basically, you siege, attack by merely parking your archers in a right at your spawn, (or if needed advance so that they can actually hit stuff), line up and have them shoot until they expend all their arrows and switch to melee weapons. Make sure any of your infantry that spawn are as far back and parked as you can.
Retreat. Repeat.
Once you whittle the castle down a bit, then switch the order of your troops to a better mix of archery and melee, line up the archers and send the infantry up the ladders. You can recall them after then get to the top so you surge and charge a few times. If you manage to get a group of your guys over the wall, then go all in.
With this tactic, I have taken castles where I was outnumbered 3:1. If you get knocked out though this falls apart.
Having a superior archer line and the infantry composition makes a difference in how best to use cavalry.
The enemy has better/more archers, same infantry levels: Go and slaughter the archers, sure your footmen will get more losses to their cavalry, but a freely firing archer line, if they aren't Nords, can be devastating.
Same archers, more infantry: Try joining the fray on the flanks, or even better from the rear. Wherever their infantry faces to deal with, they will be vulnerable from the rear to the rest of your army. In this case fast death dealers (short weapon, nasty swing) will be much more useful.
If they have hard hitting cavalry the best you can do is to engage them with your own. A close matched infantry skirmish can fast become a massacre with a bunch of heavy charging cav with spears, as these tend to keep the enemy -you!- at arms length while their buddies slaughter those who fall down from the initial charge or the impact of horses when things become a giant melee ball. If you send your cav to meet theirs however, your footmen will have more time and chance dealing with their enemy.
If you are Nord, and it sounds like you are, then your guys have slow horses. That means your companions will have to be more active in mopping up the light armored foes. To this end, I'd suggest lance/shield combo, and on your part, constantly looking up where you can strike hard. Your cavalry still should function according to the cases above.
Best Answer
If you're marshal and summon your forces, they will always attempt to come directly to you unless you've spoken to the lords indiviually to give them different orders. There are other scenarios where lords won't come directly to you, but these can be vaguely summarised as prioritising 'household business' over 'realm business' (for instance, they may be low on troops). Lords may also fail to attend if they're feasting, but usually the marshall's call will end active feasts.