Herbie side drilled

[Mmsetta]

Why do all samples of the herbie style overflow that are drilled from the back (not bottom) show a right angle down into the water for the main over flow and then the safety line has the right angle facing up. Wouldn't it be more efficient to have both with a right angle or "u" facing up so that the water flows with gravity down the main line. Then, you can just drill the hole a little lower for the main line and have it sitting lower in the tank for a full syphon.

Anything wrong with this? Both identical right angle adaptors attached to the bulkheads, just one lower than the other?

Sorry so wordy, but wrapping my mind around all this.

 

[143MPCo]

this might help better than an explanation?
To help with the gurgling a 90 degree is added.