Trying to work out what tree will suit a corner of my garden!

[CatNamedEaster]

I'm looking at doing work in our back garden as I'm fed up of having a trampoline being the dominant feature! It is west facing, and the back border (brick wall) has a large conifer in the southern corner, a pittosporum next to it, then in the northern corner (but about 5m in from the back wall) is a huge magnolia.
My plan is to remove the magnolia (I know, it's beautiful for two weeks of the year, but two of the branches are so far-reaching that the back of the garden is completely unusable), put the trampoline in its' place, and hopefully add a new tree to the northern corner of the back boundary.
It's really hard to know what will do well there though: our soil is clay and in theory the spot will be sunny east and west facing (as the conifer and pittosporum will block sun in the middle of the day) BUT searching for something suitable for clay might not be the way to go, as I'm assuming the soil will be really dry due to all the tree roots?

Should I be ignoring what my soil conditions are and be looking for a tree that will suit poor soil conditions because of the exisiting roots? Should I look for something that will do well in sun (even though the bottom of the tree will always be in shade) or shade (even though the branches and leaves will only be in shade in the middle of the day)?

I get the feeling I'm totally overthinking this !

Please consider the grown size of the tree you are planning on planting first and also whether it sheds leaves and acorns / seeds etc.

Look at the direction of the sun, will the tree cast a shadow in your NDN's garden for most of the day?

I've been looking at ones that grow to a maximum of 6-8m height but with upright rather than spreading branches, so that it doesn't overhang into the back neighbour. They already have shade cast by the existing conifer and pittosporum until approx. 11am but the new tree wouldn't cause any additional shade as it would be 'behind' the shade of them. We get on ok with them, and have recently had the pittosporum tidied up to remove a branch so they had room to put a patio and tall pergola at the back of their garden. The neighbours to the side already have tall trees at their back boundary so it wouldn't cause a new issue for them either.

Hopefully this pic will attach:
(3) is a hazel tree, quite open and still lets light in.
(2) is the conifer
(1) is the pittosporum
(5) is the magnolia that will be removed
(6) is hopefully going to be the new tree.

There's no issue with impact on neighbours as we are on a hill, so the person to the left gets sun all day anyway, then there is a wide path between us and the neighbour on the right plus they are uphill and have their own tall trees.
My only concern is what sort of soil conditions trees will put up with: it's clay but might not be moist due to all the tree roots already there, but then again that corner (6) will be in shade at ground level for most of the day even though the trunk and branches/leaves will get sunshine to mid morning through our garden, then from mid afternoon through the back neighbour's garden. So a real mixed bag of conditions!

Would reducing the magnolia be an idea? You could take out the annoying branches and see if that helps, before taking it out altogether.

How about an amelanchier? I can't have one as they don't like chalk, but people on here rave about them.

Or an acer?

Try the RHS's Find a Plant

Are you just replacing like-for-like, does it have to be a tree? You could do something different - a seating area, pergola, water feature, etc.

I've tried my best to keep the magnolia but if I chop the branches back that are intruding it would look terrible, like a tree that has been split down the middle!
Amalanchier is one that I have thought of, and there was a Rowan that looked ideal too. I suppose I need to take a good look at the soil once I start digging so I can see what sort of condition the new tree will have to put up with.
I thought of a tree rather than a nice feature only because the end of the garden will be a bit of a secret/play area so It's more for a nice backdrop than to be a feature in itself.
I guess a pergola with climbers might be an idea too though, could be good for kids to use as aseating area.
I'll see if I can post a pic of the magnolia and the corner. Might not be clear but the magnolia branch sticking out to the left goes across half the back width and if I tried to keep it but lopped those branches then it would look very weird with just two branches straight off to the right of the trunk!

We have clay soil and habe several mature camellias, they are my favourite, if you go that route though add some soil in when you plant it up. Camellias also love shade. Some of them grow very large, I have some about 25 foot. Some much smaller, some very wide. But you can easily keep them trimmed. They are slow growing though.

Ooh I didn't realise they could be so big, I had a couple in pots years ago! I'll have search for those too and would definitely need to trim it or choose one that is more columnular rather than wide.