Looked at my 2 well behaved colonies recently and am I confused!

Colony 1 (best queen) on 1 & half brood boxes, found 2 queen cells
(with very young larvae) on the bottom of a top shallow frame.
I thought supersedure cells were usually in the middle of a frame and
swarm cells were more numerous. So what are these?? The Queen still
looks good and is laying masses of eggs.

Colony 2 on 1 brood box, again 2 queen cells, 1
sealed (missed my last inspection) in middle of 1 frame. Are these
supersedure cells for sure? In my inexperienced panic I did an
artificial swarm (can't afford to lose a swarm with my
neighbours) I
took the frame with the queen and put it in a new brood box with
fresh foundation. The queen looked as big as ever and the brood pattern was
excellent but there were few eggs (could be lack of space)

If these were supersedure cells will my bees make another?
Is there a 'sure fire' way of telling the difference between swarm cells and supersedure cells? (has to be fail safe)

(Berkshire UK)