Done it many times. Shouldn't be any serious problems, just make sure that the NC aux contacts of both overload relays are in series so that if one motor OLs, it shuts down both motors.

If you are going to use a Soft Starter, it's usually OK to start one motor with the soft starter and start the 2nd motor Across the Line after t gets to full speed. But that does also depend on the mass of your rotor, the stiffness of your line, the voltage drop you can tolerate and the ability of your supply transformer to sustain a long acceleration time. If you have to accelerate as fast as possible, you may need one large soft starter to control both motors simultaneously.

If you plan on braking that chipper, that will force you into a single controller as well. To determine f braking is necessary, look at your production values and spin-down time. Generally if this is a waste reduction chipper, braking is pointless. But if it is a production chipper and you have a proscribed knife replacement schedule t optimize throughput, braking will increase your productivity well beyond the cost of adding the braking system. Something to consider.

Yes, belt slip is a concern, but in general, it usually evens out if both motors are identical. When one set of belts slips more, it's usually the result of a step change in the load, i.e. when you feed a log in. One slips, the other motor takes more load, but it increases slip, which increases current, which increases torque, speeds the load up again and the first motor belts stop slipping. One thing you can do s to put ammeters on both motors and watch the differential. If t gets to be more than a couple of percent, you are getting in trouble. I have done this with a simple little PLC that is taking in an analog current value from each motor, then calculating that differential and triggering a warning.

Where it really becomes a problem is if the motors are not identical, because it can start off an oscillation that it may never recover from. The only effective way to use non-identical motors is to put them both on VFDs, which is generally cost prohibitive if there is no advantage to using the variable speed capability, and in chippers, there is no advantage.