Synchronized signal responses from multiple arduinos

I plan on having three arduinos hooked up to each other and each one is connected to a device that sends out a signal. Sometimes each signal has to be pulsed at the same time, within a single millisecond of each other. I am consider using the I2C Master Writer/Slave Receiver (https://www.arduino.cc/en/Tutorial/MasterWriter) where one arduino is the master, send its own signal and then commands the other two to send signals as well. I am new to understand I2C so I would appreciate feedback.

Are you using I2C for a specific reason?
If the only requirement is to send a trigger signal with minimal latency, why not use a digital output from the master that connects to a digital input on each slave that triggers an interrupt?

I thought I2C was a good way to transfer information between them in general, using a digital signal with an interrupt would definitely be faster. Thanks!

Now that I'm looking at it again. I need the signify to the slaves the strength of the signal. Is it possible to send information with an interrupt?

operl:
Now that I'm looking at it again. I need the signify to the slaves the strength of the signal. Is it possible to send information with an interrupt?

You could vary the length of the of the trigger pulse to indicate what signal strength is required, but that will probably involve more work than simply using the SPI, serial or I2C libraries.