Tales of the World Radiant Mythology 3

[Arala Cran]

In a story-oriented mission I have to go with Senel alone in the underground area where strong undead enemies are.

There's one problem however which then withers our HP resources down despite being level 52 here. This puzzle in the displayed image I have screencapped:

h--p://i4.photobucket.com/albums/y127/EtnaDarkXiaoyu3/VG%20stash/puzzleodoom-rm3_zps8wtytrsl.png

Is there any solution to how to get the switches set in this order in a quick way before the monsters kill us completely? It's kind of, well... complicated. One switch being shot triggers the two to its left and right to pop out. The sides, I can figure, but the middle to get two to stay together or both popped out is confusing. Could someone provide a walkthrough or quick info note of how to deal with this?

I'm kinda stomped, lol.