Since I am using Wicked on my system I see no need to keep NetworkManager installed.
However trying to remove these packages it would also remove plasma5-session

The following 13 packages are going to be REMOVED:
libNetworkManagerQt1 NetworkManager NetworkManager-lang NetworkManager-openvpn NetworkManager-openvpn-lang NetworkManager-pptp NetworkManager-pptp-lang plasma5-session plasma-nm5 plasma-nm5-lang plasma-nm5-openvpn plasma-nm5-pptp plasma-nm5-ssh

Why does plasma5-session need NetworkManager?