Sounds like the roundabouts are too small to function the way they are supposed to. We have a couple of those in our town, also. If the roundabout is the right size, then you yield to those who are in the circle. Problem is when you are out of the circle almost before you are even fully into it.
Of course, then you also have the people who think a roundabout is just a big, 4-way stop. So they sit and wait for people who are clear around on the other side of the circle, when there is no conflict at all. Or the ones who are in the circle, and have the right of way, but stop anyway (those are the REALLY stupid ones!).
A roundabout is specifically and deliberately NOT a 4-way stop. Just like a yield sign is specifically and deliberately NOT a stop sign. Amazing (in a very sad sort of way) how many people cannot understand these very simple things.