How was I supposed to know the order to hit the switches in Sky Keep?

I just finished the last temple in Skyward Sword, Sky Keep. In one of the rooms (the one inspired by Eldin) there are three switches you have to hit in order for the locked gate to open.

I couldn't figure out what the required order of hitting the switches were, so I had to brute force my way to the solution: 2-1-3 (if I'm not mistaken).

How was I supposed to know this without guessing? Were there any clues that I didn't catch?

Solution 1:

There is a stone tablet in the room (next to the closed gate) that tells you what you need to know. It says something along the lines of (I don't recall the exact wording):

Hit the switches from lowest to highest.

So of the three switches, you need to hit the one at the lowest elevation first (the second one you see down the ramp), then the one at the middle elevation (the first one you saw) then the highest elevation last (the last one behind the trees).