Changing mind again!
The priority with this garden is to enhance privacy, cover the ugly building behind the fence but without blocking too much sun so maybe a lighter canopy.
silver birch seems nice but think they're too big? That existing sorbus looks too close to the sambucus so don't mind getting rid of that to make space.
Any suggestions? I'd like the trunk to be open so it can be walked under. Height needs to be around 12/15 feet at least?
Wildlife is definitely a bonus but not to the point of planting an ugly tree
It would get full sun in that spot.