Three-way switches can definitely be confusing, but when you do your research you need to look for networked versions.
There are at least eight different ways to wire a nonnetworked three-way setup, but many of those do not work for networked switches.
The reason is that it’s pretty common to wire nonnetworked three-way switches in a kind of figure eight so that throwing one switch runs the current through its loop and cuts off the current through the other switch’s loop. That works fine for non-network switches.
However, it doesn’t work for networked switches, like Z wave switches, because a network switch needs to always have some power or it can’t hear the next “on” command from the network even when it looks like it is off.
That’s why it’s quite common to have to change the wiring a little bit when you are going from a non-networked three-way to a networked three-way.
There’s more discussion in the add on switch FAQ: