newcastle is a great place to be (im in durham doing compsci, so neighbouring cities) - and me personally i'd look at the course first! something you'll realise is that if you hate what they're teaching you then it doesnt matter how great the city is. compsci courses can vary so much; take a look at how much coursework you'll be getting; how much practical you'll do; and for compsci, i know for a fact that both universities have decent lecturers, so you don't need to worry as much about the teaching.
take a look at why glasgow is better ranked? if it's because they have a sh*t ton of coursework AND that's something you don't mind then go for that - if you're not up for that much coursework and would rather build your degree on exams and test then maybe go for newcastle.
and also scottish unis do things a little differently, like the major minor system in america. so if you dont end up liking one subject then you can very easily change your course whereas it would be much more difficult in an english uni. so if you're on the rocks about your future and want to expand a little then maybe glasgow. although you'll probably spend a year longer at uni if you went to scotland.
so... yeah personally top 30 unis are just fine, and it shouldn't matter too much where you go as long as you like it. if i had taken my own advice a year ago, i'd have gone someplace with little coursework, because thats the reason durham is ranked so high, but because of covid, i was so depressed that i flunked most of it :/ i hate coursework lol but i can do end of year exams pretty well.
my answer, no, it doesnt matter too much. glasgow and newcastle are great unis, but they have very different courses. take a look at them
i hope this helps, and im sorry if i made your decision harder