TrackPoint Help Me please!

I m using a window manager on a Thinkpad.
The trackpoint is too fast for me and i’ m not able to control.

This is the output of xinput list-prop 14 ( which is the trackpoint id)

 ➜  xinput list-props 14 
Device 'TPPS/2 IBM TrackPoint': 
  Device Enabled (191): 1 
  Coordinate Transformation Matrix (193): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000 
  libinput Natural Scrolling Enabled (326): 0 
  libinput Natural Scrolling Enabled Default (327): 0 
  libinput Scroll Methods Available (328):  0, 0, 1 
  libinput Scroll Method Enabled (329): 0, 0, 1 
  libinput Scroll Method Enabled Default (330): 0, 0, 1 
  libinput Button Scrolling Button (331): 2 
  libinput Button Scrolling Button Default (332): 2 
  libinput Button Scrolling Button Lock Enabled (333):  0 
  libinput Button Scrolling Button Lock Enabled Default (334):  0 
  libinput Middle Emulation Enabled (335):  0 
  libinput Middle Emulation Enabled Default (336):  0 
  libinput Accel Speed (337): 0.000000 
  libinput Accel Speed Default (338): 0.000000 
  libinput Accel Profiles Available (339):  1, 1 
  libinput Accel Profile Enabled (340): 1, 0 
  libinput Accel Profile Enabled Default (341): 1, 0 
  libinput Left Handed Enabled (342): 0 
  libinput Left Handed Enabled Default (343): 0 
  libinput Send Events Modes Available (311): 1, 0 
  libinput Send Events Mode Enabled (312):  0, 0 
  libinput Send Events Mode Enabled Default (313):  0, 0 
  Device Node (314):  "/dev/input/event24" 
  Device Product ID (315):  2, 10 
  libinput Drag Lock Buttons (344): <no items> 
  libinput Horizontal Scroll Enabled (345): 1 

Is it correct to do

xinput set-prop 14 337 -0.5

in order to slow down it.
I ve tried and it works, but i’m now sure if is a good practice or there is a better way to do that.
Any suggestions ( I’m aware of this https://wiki.archlinux.org/index.php/TrackPoint but is not been very helpful)