It depends if your machines are belt/gear drive or direct drive.
If they are belt/gear drive then run separate hoses from the tank to each machine, Don't use a "T" to save a little bit of money for the supply to the machines, don't starve them, you can mess up the pumps.
If they are direct drive, run separate garden hoses to each machine from the house. A lot of times the flow from a house is not enought for an 8gpm machine, a lot of times not enought for my 5.6gpm machine so run a hose from the house to each machine.
Once you experience the 8gpm or more, you will want to do that a lot or keep it rigged up like that. Sure makes a huge difference when running surface cleaners.