Yes, its likely less, but likely not by much. The problem isnt just the Gnome desktop itself. Its applications also use a lot of memory. I know from experience that older systems have problems running it since I have very old hardware (FX4300, 560ti, 6gb DDR3), and it doesnt run very well.
Xfce should run ok. While I dont normally link to the spins I create, Manjaro doesnt have a LXQt install iso. You may want to give mine a try if you find you need a desktop and applications that sip memory.