I've never actually tried an Oirat game before, what's the best way of dealing with Mongolia? They're cockblocking me from getting to all the good provinces in the region (especially Buryatia's gold mine!) Is it worth just straight up cancelling their vassalisation and then conquering them?
I tried a quick game as Korchin instead and had much better results, unifying east Mongolia with ease, and though your starting ruler is a bit crap you get to abdicate fairly soon thereafter. Significantly easier than forcing your 1st war to be against Chagatai.
It would be nice to have at least a reasonable idea of how strong you need to be in order to beat Ming as this is my first game taking over China since 1.20.
I tried a few Oirat runs in the last 2 days with the same objective and found, that the best way to deal with Mongolia is just release it from vassalage from the start (just after Ming declares its usual first war versus Korchin, so it won't attack the freshly-independent Mongolia instead) and annex it after 5 years of post-release peace pass. After that, just go for that glorious high-dev Manchu land (i turned the 2 manchu regions bordering Korea into states without razing, as they are quite rich).
Going for the muslim clay right from the start is terrible, since you either have to make Sunni syncretic which takes away the glorious Tengri bonus of -20% regiment cost or suffering heavy losses and constant rebellions for nearly-useless land that is also nearly unconvertable. Manchu lands will give you the necessary manpower and tax income to fund the further wars against Korea for even more good states and and making dealing with all the sunni-clay rebels much more manageable. Also always take as much money in peace deals as you can.
Also, the province of Hami, owned by Kara-Del at start is nice for developing feudalism/rennaisance). Increase relations with Ming and improve it a few times so Feudalism gets a decent spread-speed in it (i upped it until it got a ticking +1%/month)
As for taking on Ming, i did it in 1530 with a 50k army, 2 miltech advantage and 0 mandate for Ming. My 30k stack was 10-15-5
P.S: For the extra awesomeness, take the "Transfer Subjects for Half-Price" as your first Age of Exploration ability and get that Yarkand from Chagatai as your loyal lackey
