Two outboards seems ridiculous to me. That makes four ways to move the boat: Two motors, paddling and perhaps sailing if she is not too heavy with motors, fuel, batteries, crew and stores to make any way at all.
All motor boats up here have two out boards. There is almost no way to call the Coasties, they are too far away and separated by 1500 foot mountains. The number of other vessels powered or sailed is extremely small---most often zero.
There are no marinas and the nearest tow company is nearly 70 miles away.
If your primary motor dies, and the wind either dies or turns nasty, then you will drift until you flounder on a sharp rocky shore with the tide. Up here you are on your own if you experience a motor malfunction and weather or wind or waves either die or get nasty. Paddling in impossible. and when you sink due to hitting a rock in the middle of the bay or on a shore---still no one will even see you there.
After having my primary motor die last year, being unable to reach anyone including the Coastguard, and drifting backwards on the 12 foot tide for 5 hours, heading toward rocks, where the water is way too deep for an anchor, we were very very very lucky that someone heard our mayday after 5 hours and in the dark. Most of the sailing was on a bright sun on a beautiful day.
If you sailed where I sail, believe me when I tell you, you would seriously think about another motor as back up. Everyone does.
Since you have no answer to the required equipment where I sail, I guess that I will just have to deal with the consequences.