Sungazers are awesome. They're so awesome I decided to base some parts of my dragons' appearance on them.
Dragons in my setting are hexapodal, roughly horse-sized, omnivorous creatures with human intelligence, maybe at around 300-400 kg in weight. They use unlikely, but biologically synthesizable materials like graphene in their body. The setting has guns and (wannabe) dragon slayers, but magic will take care of those for now.
I despise spiked armor (but in all honesty, it looks cute on sungazers), but I want to keep it for now. I want to feel better about my decision, so I need an excuse. This excuse should be a practical advantage that spiked (natural) armor grants. Being a way to attract mates is an aesthetic reason, so it won't cut it.
What would be the most important practical advantage spiked (natural) armor could grant for dragons?