Although this is correct, this may lead to a tiny flaw.
Let's assume that you use a 20t/s clock. If the command blocks are placed in a way that the tp command that teleports the entity -1 y coordinate lower is nearer to the source of the clock (Nearer to the two command blocks running the clock), then chances are the -1 y command will run first, therefore rendered useless. I already tested this and it seems like the logic of the clock is the one that is nearer to the source is the one that first activates. But I am not sure if this is affected by the East/West direction. My solution would be using the add parameter in the scoreboard objective and only teleport the entity -1 y lower if the score is 2.
