Again, there is no way to merge partitions, logical or otherwise and you certainly cannot join discontinued space as in your situation. I suggest you do as your friend advises.
With a third party disk management software, you can move partitions around but you still cannot join discontinued space as you suggest, and it is very risky.
Maybe discontinued is the wrong word, perhaps non-continuous would be better or not adjacent space. But you cannot do what you suggest and combine non-adjacent space.