The Xclients script has a catchall at the bottom, which runs
RunWM --Fvwm95, and then, if this returns an error, runs
fvwm. However, RunWM won't return an error, as if Fvwm95
isn't found, it runs twm instead, and so Xclients never gets
the chance to exec fvwm.
Unfortunately the current settings in the AnotherLevel do not permit
running on a system without fvwm2 installed at all. If RunWM will
return an error when no fvwm2 is installed the window makangers
switching can experience problems.
It is far easier to use the .Xclients for those die-hard old-days fvwm