I've played plenty of warband and already put hundreds of hours into bannerlord experimenting with different things it had to offer. I usually play sandbox (I've done the main quest a dozen times back when it was alpha) and I get somewhat far into it. I'll go around and do tournaments, fight bandits, recruit soldiers, etc etc. I don't usually like becoming a vassal because it feels like I should solo start my kingdom without the help of another culture, stupid perhaps, but I like the feeling afterwards. However, when I finally get down to either maxing my party size, usually at close to 100 or so when I level my character and have a good quartermaster, or I'll capture a castle and try to start capturing a city but either can't because I don't have enough troops or because the nation I took the castle from is trying to steal it back everytime I go to take said city. I can't really wrap my head on what I should do after I capture a castle/few towns. Is there a way I can expand my kingdom quicker or am I doing something wrong?