>>106215196 (OP)
Mate is, generically speaking, more "complete" than xfce4 in terms of utilities but being the gnome2 fork it's essentially abandonware (even though it was ported to gtk3). Xfce4 conversely has less componenrs but is actively developed.
Imo i prefer xfce4 because is more granular and configurable (and doesn't shit it's pants with some themes).