I think it all comes down to circumstances, judges, confidence and resilience.
I had a Direct Access Barrister for my FHDRA which was a complete waste of money.
As a LIP I have challenged x2 NMO and won.
I was in a 4 day FF against a barrister and won.
Im not anything close to a professional and I do not have any legal experience but I know my case and I educated myself with the help of this forum, YouTube, Child Law Advice and researching cases and outcomes.
All we can do is our best, I have been stressed up to my eyeballs with administration, dealing with my ex's slimy solicitor and everything else which comes with the journey but self care and short breaks do wonders for your mental health.