2 destroyed starters in a row...WTH?

A couple of things. The quality of the steel used in the ring gear. Or heat treatment? I've never seen a stock ring gear tooth break off, but I've seen several teeth wear sideways from a sticky Bendix.

The old 440 HP motors came with 500 CCA batteries. I'd bet yours has much more. Too much power [torque] for one tooth to handle? ---- Combine this with a stray spark and ????

I might try a 2 second time delay for the ignition on/start system. Let the engine spin up before the spark plugs light off. I don't know how to do it, but there are some sharp minds on this site.