How much differance is there?
Most often 1/4 sanded subfloor rated plywood is added to built it up, it also comes in 1/2 and 3/4".
Any subflooring has to have fastners every 4" on the edges and 6 to 8" in the field, and never attach it where the floor joist are, Your trying to take out the tiny gaps between the joist. Never glue it down.
It would be best if the base boards are removed to do this.
Do not use louon plywood!