Breaker Trips when turning on saw
I believe your problem is the extension cord.  Is there any way you can locate the saw(s) so that they can be directly plugged into the outlet?

What happens when you use an extension cord with an induction motor (which is almost certainly what you are dealing with) is that there is an initial surge of current until the motor builds up a resistance (called back EMF) as its magnetic field starts to stabilize.  When you use an extension cord there is voltage loss across the cord and so it takes more current to generate the back EMF.

Another possibility is to get yourself a heavy duty extension cord so as to minimize the voltage drop due to the cord.  These are generally more expensive since they contain larger copper conductors but may help resolve your problem.  I realize your cord is marked as "heavy duty" but it's a 12 ga cord.  A 10 ga cord is probably a better choice here.