Airsupport,
Gotta back up Devillanddriver here. MOST twins these days operate on 180 min etops. However, by your reckoning, an engine out half way across the Atlantic, or the Tasman for that matter, would require an imediate ditching due to an impending failure of the second engine. Excluding fuel exhaustion, any aircraft operating under 180 min etops can be a max of three hours away from an alternate on one engine.
Your insistance that aircraft land overweight due to a single engine failure alone seems ill-informed.