I have a couple of examples for you, to show that there is no consistency. That houses, and wiring, can all be individual.
1. I worked through the speed estimates of all the properties on my (previous) 1990's estate, and noticed an interesting effect.
The estate was mostly separate houses, but there were 5 blocks of apartments dotted through the development.
The estimates were all sane for the houses, in proper proportion to the distance from the cabinet. However, all the flats had markedly higher speed estimates than the houses on either side of the block.
When comparing the blocks alone, their speeds dropped off correctly with longer distances... they just dropped off slower than the houses.
The conclusion I reached was that the apartments had been wired with broader gauge cable than the houses - probably 0.7mm cable instead of 0.5mm.
2. My current property is a flat in a converted house (from more like 1890's); the speed estimate for the 3 flats is considerably higher (60-80) than either of the houses on either side (35-47).
I always thought it odd that this house/these 3 flats were wired to a different cabinet than the houses on either side - but the street distance to both cabinets is identical. Cabinet numbering (one is cab 22, the other is 119) suggests that one cabinet was added a lot later, perhaps to overcome congestion - even though both supply an area of 100+ year-old properties.
Then I discovered that the cable routing takes our phone line out the back of the property, overhead, and along a back alley rather than out the front, underground. The different routing saves perhaps 20-30m of distance, but that alone isn't enough to explain the difference in estimates. The rest of the difference probably comes from the gauge of the cable, or its age.
Strangely, the estimates weren't originally as profoundly different as they are now. When I moved in, our estimate was around 55Mbps, while the neighbours were around 45Mbps.
3. That difference is nothing compared to the last house on this street. As the last house, it is close to a T-junction for a cross street, at the far end to either cab 22 or cab 119. For some reason, it isn't wired to cab 22 like its next-door neighbour, but is connected to the same cabinet as the houses on the cross street. That cabinet is on a different exchange, and only got upgraded 3 years after our exchange, so they had to be a little more patient.
But the patience must have paid off, because they got FTTP instead.