I have a question on this topic.
I'm not particularly good at M&B and usually play at the wimpiest difficulty, especially in Pendor since it's hardmode by default. As a D'Shar lord, I have just founded my Order of the Scorpion and am now wondering: what should be upgraded first, armour, horses or weapons? Should I get top-of-the-line stuff immediately or upgrade to something halfway decent first? It takes 70 days to get my knights in all plate and I'd rather like to use them before that, but that would delay them being OP even further. I only have about 100.000$, Sarleon, 2 Castles and 2 villages.
Currently, I'm not even using my order troops. If I want Things poked with Sticks, I can get raw recruits from villages.