'TEM' and Maths

I'm thinking about Technology, Engineering and Mathematics (mainly tech and maths) and struggling with the problem that whilst I'm good at Maths (maybe even very good - top 6,000 or so my year in the UK, got A* at IGCSE with 95% although I know that means basically nothing), I'm not exceptional/near genius.

I don't know what I want to do with my life exactly, but in my own naive/selfish/optimistic way, I want to reach somewhere near the very top of whatever field I go into. I feel like I can't do this with the 'TEM' fields - I can put all the hard work in the world in but so can someone else who has started off at a near-genius 'baseline'. How can I possibly compete with some of these near-geniuses, simply being (very) smart? In other fields, it feels more balanced - for example, you don't get some people who are amazingly talented at History and just completely can't be beaten if they're working hard themselves, at least to the same degree...

Am I right with this analysis, or have I made a mistake? Is it true that in these fields (e.g. programming), I'd be stuck in the middle, instead of the forefront? I know this is a very solipsistic and first-world concern, and I'm aware the answer may be that yes, it is true.

TL;DR pretty good at maths, not awesome; possible to beat 'near genius' people in Tech?

Have you done A-level Maths?

No (Year 11) but going to do Maths+FM. I've done about half the AS content though in OCR Additional Maths, and got A's (top grade) in every past paper (although the real one was very difficult for everyone).

Nice! Just don't count your chickens just yet :-) even additional maths is early days