If you are looking to run herbstluftwm with kde this bring herbstluftwm to KDE Xorg only
my systeam Arch linux - arcolinux KDE Plasma 5 Kerbstulftwm
other note Think like D-menu work along with the kde menu keybinding in kerbstluftwm work with in kde more testing is need for keybinds the config file im useing is the from acro-linux for kerbstluftwm and kde you might need to change the file path for othe Linux distor
this just a X-seeseon that let you use both kerbstluftwm and kde togther
place the new X-seeson filre in /usr/share/xsessions
you can download the github file and cp in your /usr/share/xsessions by useing cp your download fiel path to /usr/share/xsessions
Note there has been no change to config file that come with from herbstluftwm for
this still need testing i think config file herstilftwn can be change 
think like layout work just fine
[Desktop Entry] Type=XSession Exec=env KDEWM=/usr/bin/herbstluftwm /usr/bin/startplasma-x11 TryExec=/usr/bin/startplasma-x11 DesktopNames=KDE with herbstluftwm Name=Plasma (X11) with herbstluftwm