Hi,
go crazy with the number of fsms! don't worry about that for sure.
Typically, Playmaker is designed indeed to run multipl efsm, since as you mentionned, an Fsm can only have one state active at a time. It's not a restriction, it's a feature
What you need to be careful with is not the number of fsm, but what they actually do, that's the catch. Typically, don't repeat things when you can do them only once, don't "find" object everywhere, but instead manage them properly and reference them in variables at editor time or only once in a manager of some sort that other fsm will go and get, All these things are not really inherent to PlayMaker but more common practivce that must be applied within Unity itself.
In doubt, don't hesitate to post your specific feature implementation and we'll discuss it ( and don't hesitate to bump your threads
)
Bye,
Jean