Here's a great discussion of old style anchors. Guess I talked myself into a newer style next purchase.
http://www.petersmith.net.nz/boat-anchors/old-generation-anchors.php
I think an extra tweak to the breakaway style chain on the Bruce style would be to use a much smaller chain, say 500lb strength or so, from the "heel" of the anchor up the shank to where the tie wraps attach the chain to the eye. At that point upsize with a shackle to the real working chain. I think it makes it tough for the Bruce to go claw side down when there is a lot of chain weight on the opposite side of the shank. Also if you end up in the very, very rare case where the anchor is truly fouled: the weak chain right at the anchor will probably break safely and you'll only lose an anchor and a couple feet of cheap chain. You should get all your main chain and rope back: sort of a double break away rig.
Finally for you guys that are rerigging boats with twins and have the cash: you can now get Auto Pilots that will anchor the boat for you with the outboards. I think that's got to be worth a LOT in terms of safety.. Check out Skyhook Anchor for Merc but I think other brands have similar options.
https://www.mercurymarine.com/en/us/gauges-and-controls/steering/joystick-piloting-for-outboards/
Video of Skyhook in action.
http://youtu.be/uchXzhhY4ZY
just saw a vid on the weekend with the joystick control...... amazing. never seen outboards going opposite way
Evinrude eTec G2 with Optimus on a 3025 Kingfisher https://www.youtube.com/watch?v=ZXH4yK2aIWI
sorry for hijack