Not really if its was an old ford or chevy sure but here there isnt the room plus the feel of things. To get good videos with the motor inside the machine. Id tear the rear cover off. And take a look around but id do it with starter in place kinda get a good look at everything. And to tell you the truth im not even sure if thats possible what i just said i havent really been that far into 1. Replaced dads big red starter once my 2014 is still on stock starter. How old are the batteries? Before you try the new starter take the batteries down and get a load test done on them just as a 100% sure your knocking everything out running while diagnosing. Leave them on trickle over night let them stand for about 2 hrs then load test them. You could possibly be getting the volts but not the amps. But thats just a thought.
I believe the use of washers to make it line up is the key. It may be misaligned to the point the starter gear gets in a bind and doesn't disengage quick enough or sometimes not at all. This would explain why the starter gears are damaged.