I have never seen a roundabout here in Australia that allows for these sorts of conflicting movements, that would be asinine. Are you saying there’s multiple lanes that can exit or go straight such that someone in the inside lane can turn out in front of someone continuing around in the outside lane? Is this a North American thing? Of course that would result in accidents, don’t build your bloody roundabouts like that!!
I drive through three lane (six lane road) roundabouts all the time and no one gets hurt. In fact I have to drive through two such roundabouts to get to the nearest freeway.