Forsoothe!
Imperial Masterpiece
Boo Hiss. I count separate 6 trees. If you chopped all but one you would have to do something about the roots. You have a nice clump that you can make into any height clump you wish. I think the on taller side would fit nicely the thin trunks. If you attempt to remove the smaller trunks and their roots you will be left with a very ordinary trunk with lots of witness marks from the removed crossing roots. God only knows what that will look like, but whatever it looks like will pale in comparison to what you have. Decide upon a height, chop it in an arc a grow the canopy on via clip & grow. Your group looks like they belong together: they are in harmony with each other. Here are two trees with an united canopy...
And on your trunks?

A little too low, thick and overbearing, but you can mount a more delicate crown and open interior to match the trunks and open space that is there. Now, compare in your mind's eye the bulky base you would have sans the extra thin trunks and you would never be able to overcome the skinny pole sticking up out of the giant base, never mind the witness lines of roots past. IMHO

And on your trunks?

A little too low, thick and overbearing, but you can mount a more delicate crown and open interior to match the trunks and open space that is there. Now, compare in your mind's eye the bulky base you would have sans the extra thin trunks and you would never be able to overcome the skinny pole sticking up out of the giant base, never mind the witness lines of roots past. IMHO