Easy way to snap then merge a piece at the end of an array I'm fairly new to Blender and I'm trying to make a railing on a roof top.

I made the base shape, added array modifier then applied it.

My problem arose appeared when I had to make the ending of the railing. I copied one of the tall supports and moved it to the end.

I don't know how to make it snap to the bigger shape and then merge the edges so it's one seamless shape. I tried turning on snapping during transform and selected edges, faces and vertices but that didn't help, it didn't snap to the correct place.

Another thing I'm wondering is if the method I used to create the thinner bars is correct. I subdivided the top bar in sections, insert and extruded the bars but I didn't merge/fuse at the bottom, is that OK?
On the Array modifier you can use another object as start or end cap;