Hi
@futuretraineesolicitor, I hope you're well! I had the same dilemma as you when I was making applications and realised that thinking outside the box for my cover letter when my application already states my more obvious/attention-grabbing achievements helped me resolve this.
For example, if you want to talk about your ability to break down complex information in an accessible way, try thinking of instances where you have done this in a group project, volunteering, as a member of society, while organising an event, in your part-time job etc instead of just the competition you secured third place in.
If you're not able to talk about a competency/skill with the evidence you would like to mention without risking repetition, then I would encourage you to find other competencies/skills that match the firm's criteria and elaborate on that through the evidence that you have. Usually, firms list these on their website or mention them more generally in the sections where they elaborate on what the training contract/vacations scheme entails.
The only situation in which I would repeat information I have mentioned elsewhere in my application is if I am providing new context. So if you've mentioned that you won XYZ competition and honed your teamwork skills through it, I would only mention XYZ again if you talk about something new, like how you demonstrated your creativity through it.
Lastly, I would be careful about stating achievements and related skills and leaving it up to the reader to deduce how they're linked. When I worked as a journalist, it was obvious that being creative was a big part of my career, but how I applied that creativity, in conjunction with my other skills, was up to me to demonstrate to the reader/interviewer, and I wish I learnt that earlier in the application process.
I really hope this helps! 😇