If we assume that this thread is obviously meant to refer Zoro, then what Linlin suffered was way more significant for the fight than Kaido's scar. Kaido entered his actual, most demanding versus with the new scar on his chest (from which he didn't even fall to the ground nor was incapacitated at all). Linlin, on the other hand, got her arm completely non-functioning and it would have stayed like that if not for her devil fruit; imagine a fighter, and even worse, a weapon wielder losing one arm. That's devastating if the bones broken are relevant; for comparison, Sanji was worried by a crack on his leg from Vergo —that wasn't even broken— and would have been done from Queen's snake but after defeating Mr. 2 he commented on how he broke some bones again.
Overall, scars are scarcer because they hold symbolic weight (they "itch") and design-wise it would be impossible to handle many of them happening. Some of the wounds will stop you from keep battling once done (Zoro's chest scar) but others are next to irrelevant (Zoro's scar on Kaido), but same can be said for bones (Zoro's defeat was sealed after Hakai, same for Sanji after the sanke if not for his regeneration). So, as usual, nothing is more impressive than the other and it's up to context and Oda.