Don't worry, I guess determining insect species is not easy for you, but can you imagine that it's really very time- and energy-consuming for me to discuss every second day with various users the differences between bees, wasps and hoverflies? :-)
Did you also see the triangle-shaped pattern on the back of your #6 and compared it with the photo I showed you?Did you for example read the link concerning the number of wings in bees? It's four, and your hoverflies have only two. That alone is enough to exclude the option it could be a bee. Then the post from @dannewton shows a haltere very well, right?
I hope all that helped you a little bit.