Yes, there are typically many, many possible solutions to a problem.
You pick the one that works best for you.
I took one look at the two motor Z setup (without a sync belt) and said "no way".
It is incredibly easy to torque the bed support plate out of level if they are not synchronized (try it, you'll see).
I disliked the dual motor setup so much in fact that I almost bought a different brand of printer.
So my printer had the pictured belt fitted during the initial build process, and it has worked perfectly.
Others have posted their own solutions (some quite clever) but all address the same basic goal.
BTW, I haven't had to re-tension the belt even once and never have to think about bed leveling.
I have had no trouble with the Y motion other than the usual belt stretch.
But I also use load spreader washers at the critical attachment points so they don't move around.
I think I have had to tighten them once in the six months I have been using the printer.
I fitted rubber step motor damper mounts and diagonal frame braces in critical areas.
What a difference!
Now it is so quiet that I can't hear it when I leave the room (I used to be able to hear it from the other end of the house).
And the frame does not flex.
The machine no longer tries to vibrate itself to pieces.