That's pretty unlucky, also you need to turn off one of the switches to reach the boss you don't need all of them. And escape while in battle helps. Don't forget to synthesize salves, use battle synth to heal more.
This area is hard enough as it is without needing to respawn enemies 2-6 more times. Just make those two switches an OR gate. Or have three locks on that door, if you really want to use both switches.
