Best Practices on Organizing Behavior Trees

Hey there community and maybe an Epic developer!

I was wondering if there was a best practice in terms of organizing behavior trees and blackboards. Let’s say I have an AI with a few basic states: Idle, Patrolling, Suspicious, and Combat (Combat having additional states within itself). Should I try to organize all the behavior for an AI character in one BT/Blackboard, split them into two (one for combat, one for the rest), or have individual behavior trees for each major state of an AI? Seems like the latter would get tough to manage and require a lot of behavior tree switching in the controller blueprint, but it also seems like keeping everything in one tree would be ridiculous in its own way. Is this just a matter of individual taste or are there actually any performance implications?