I'm not sure what you mean by "fence like pieces" but the second picture shows the crosscut jig which is removable, it just clamps to the workbench at each end.  The first picture is just the workbench and the only loose pieces are the tools sitting on and under it.

I don't think you really need an overhang for the top, however.  The vertical ribs are only about 1.25 inches wide where they are cut out so that plus the top means you have to clamp 2 inches plus what you are securing.  But in most instances, I do not clamp this way.  One of the big advantages of all the holes in the top is you can insert a clamp in them and clamp there.  I use a couple grizzly track clamps because I got them for $25 (for two) at Christmas time.  I also have a couple HF quick clamps that I modified and use (take the fixed jaw off, heat the bar to cherry red about 2-3 inches back from the tip and then twist it and turn it 90 degrees (to make a new fixed jaw).  Cost for those is really, maybe $5 each.  You can use Festool clamps but they are $30 or more each.  DeWalt track clamps won't work but Makita probably will.  Anyway, I mostly clamp to the workbench surface using the holes, not out along the edge.  But if I want to clamp along the edge I can.

The crosscut jig is an important extra.  It has a movable stop for repeat cuts and will reliably cut 3 feet pieces square.  Only takes a couple minutes to put on and off the bench.  The combination of the bench and crosscut jig really increase the usefulness of the track saw.  Much the same functionality of a MFT but much larger and cheaper.