Is the A6 from 2017/18? Should be fine with anything. My wife's laptop is from 2010/11. I tried all the DEs because of the lightness claims, I found GNOME worked the best, and it is super peppy running NixOS.
I asked online why GNOME would perform better than what is assumed a lighter DE, and a comouter dude says GNOME goes and gets everything it needs and caches it when you launch something so retrieval is faster in the app, KDE loads stuff on demand as it is asked for so a alow CPU and HDD hinderes KDE for me.