Can I use Adjustment to change my Uni course? (Read below)

Ok, so I've applied to do Psychology at Uni, however I'm having doubts as to whether this was a good choice or not and I am wondering whether I should have chosen to do a Degree in Ocean Science instead.

At A-level I do Physics, Maths and PE, but I chose to apply for Psychology because I did a few Psychology courses online which I found quite interesting and the degree modules look really interesting.

I've received offers for Psychology from all the Universities I've applied to, but I've only got eyes on one Uni where I really want to go.

The trouble is that I think I should have applied for Ocean Science at this Uni instead because it has:
A) Higher Student Satisfaction (difference of 12%)
B) Higher Graduate Annual Salary (difference of £2,500)
C) I've discovered that Psychology is very popular and oversubscribed (whereas Ocean Sciences isn't) therefore it would be easier to find work with an Ocean Sciences Degree.
D) Ocean Sciences is more of a STEM subject than Psychology which makes it probably more valuable.

Maths is good, but I don't love Physics, Biology and Chemistry to be honest - I can live with it though. Whereas although Psychology looks super interesting I've never done a proper qualification in it before, so I don't really know. I'm very undecided.

At the moment I'm not planning on changing my decision on doing Psychology, however I want to ask this question in case I do change my mind:

Last year Ocean Sciences was in Clearing at the Uni I am applying to this year. Therefore I was wondering if it appears in Clearing again this year could I use Adjustment to switch to Ocean Science at the same University (given that I meet the requirements for Ocean Science). Is this possible or can I only possibly do this if I exceed the requirements for Psychology?