The unified memory actually means more RAM usage as textures that would only exist in the GPU RAM now have to live in the unified RAM. Unified memory is a great performance improvement but I don't think it translates into lower RAM usage.
What if you are barely using that GPU though? Wouldn’t most the GPU RAM just be wasted while you did CPU intensive tasks?
Likewise in your example you might be using the GPU more so less RAM could now be allocated to the CPU to improve GPU performance by more efficiently using the available RAM