If your geometry is messy like you suggest, the best advice I can give you is to recreate it. Your geometry in the attached screenshot is easy to recreate as it only needs creating once and duplicated another 3 times. Use tools like snap and/or parametric geometry to help start. Sometimes, trying to do things a quick or automated way can take longer than simple recreation and can lead to undesired results.
If you do want to try using Optimize, the only way it may work for you is to select the geometry, right-click and instead of just clicking on Optimize, click the black cog wheel icon to get to the options. Make sure you tick Polygons, Unused Points and Points and then experiment with the increasing the Tolerance number until you get a desired result. Be warned though, this may not help at all or make it worse.