Best way to acquire commander traits in CK3?

[Rhaeven]

I've only managed to acquire some somewhat randomly as I pursued martial lifestyles, does it matter which of the trees you choose? Do you still get traits if you command armies yourself? Does the "Train Commander" Marshall assignment affect you if so?

And last but not least, which is the fastest way to acquire those traits?

[BaCaz]

To my knowledge, you as a player can only aquire them through random events while in the Martial Lifestyle and it doesn't matter which tree, but I suppose it would be possible to get them from a commander training you but I'm pretty sure it would require your liege to have his marshal train his commanders, and you being one of those commander's. The only traits you can get from commanding directly (iirc) is Crusader and Viking/Raider which you get from commanding an army doing a crusade and Raiding a bunch respectively. I don't know any fast way beyond rng while in the marshal tree but I'd imagine that higher marshal skill possibly also prowess might increase your chances at least it will help you learn the skills and i know that a good marshal teacher can also give you commander traits when you finish your education.

[Rhaeven]

I see.. I was hoping there would be more flexible ways to acquire commander traits directly besides 'Crusader' and 'Raiders'. I might be wrong but I seem to remember that in CK2, if you commanded an army, you could acquire commander traits from time to time even if you had a different lifestyle focus than martial.