Whilst i've been guilty of landing straight-in in before an aircraft already established in the circuit, it has always been done by asking if the right of way aircraft would mind and by adjusting speed to ensure no conflict. And if it is company traffic we arrange (in a CTAF situation) to have the most expensive aircraft land first if its a tie.
I've had the same right of way problem with a F100 crew reporting their distance and estimate two to three minutes ahead of us in a B200 so that we end up slowing down to arrange separation - only to find that we arrived in the circuit simultaneously - they could have just let us go to get out of their way....