Those trees look decent!!! How long do these type of trees take to "get comfortable" and fill out?
London Planes.....are very columnar, one reason they were chosen, another is tolerance of urban conditions.
So they won't 'fill-out' as such, that much.
They will get taller, and a bit thicker, but they tend towards a fairly tight branch structure, very vertical trees...not big spreaders.
Honestly, they should look quite good, but I'm a little saddened they chose a non-native tree.
There are a variety of native choices that would have been excellent, but landscape architects aren't the most thoughtful people, LOL
Given the superior Planting conditions......I would have considered Bur Oaks, Silver Maples, White Birches, and probably White Spruce.
All native, year-round beauty, built-in Christmas trees, and fairly pollution tolerant, with the exception of the Birches, which I picked mainly for the pretty bark. If you skip over those, some Trembling Aspens would have been a fine choice.
Just saying...
Still, a huge improvement!