Hobby or Merlin description only Northumberland UK (1 Viewer)

I know I'll never know for sure what it was but I saw a small Falcon near Wooler today a bit distant and no bins but I am quite certain it was either a Hobby or a Merlin(too small and slim for Peregrine,too short tailed for Kestrel etc and I regulary see both those species there) both Hobby and Merlin are possible as I've seen and photographed both in the exact same spot before but Hobby would be a lot more unusual.

The thing that got me thinking Hobby was the fact it was pursuing a Hirundine with great agility and speed but also at a good hight (maybe 100 yards or so up) and this continued for several minuets, I have seen how fast and agile Merlin can be but don't remember seeing them do it for lengthy periods or up a hight it always seem to be quick chases close to the ground that I've witnessed.

So the question is does anyone know if that sounds like normal Merlin behaviour as it's something I'd normally expect to see or associate with Hobby.

I've seen Merlin going up pretty high for long periods chasing Skylark - say up to about 40m.

I can't tell from the description, but I imagine on range alone Merlin would be rather more likely than Hobby in the North-East.

I've seen Merlin do long chases after hirundines - so no hard evidence either way. Could still be either.

Thanks, I thought that would probably be the case.