It'll be broken down into 3 Categories Strength - We have seen feats from the both that prove their strengths unrivaled in their universes, Knuckles has feats such being able to knock out sonic while he was in his super form, Its said his strength is on par with sonic's speed even being able to overpower people such as Shadow. Broly was able to fight back against Super Saiyan Vegeta in just his base Form and even make him go SSG, once he activated His Ikari/Wrathful state he was stronger than both SSG Goku and Vegeta, and even held his own Against SSB Goku which is on par/stronger than Super forms. Broly Takes the Strength category Speed - Knuckles was never really as fast as people such as Sonic, Shadow, Metal, Silver, Etc. But he was still decently fast, Meanwhile Broly is able to out speed and overpower both Super Saiyan Blue Goku and Vegeta in his SSJ Form, Even being able to keep up and Continue pressuring the fusion of them both Gogeta. Broly Takes the speed factor. Durability - Knuckles is able to survive being frozen, resisting cosmic radiation in space, and withstanding electrical attacks, even being able to tank and strike back against Sonic and Shadows rapid attacks, Broly was able to fight for a bit in Lava, Though when in Base Form was getting rocked by SSJ Vegeta, Then SSG Vegeta, Once He entered Ikari, he was slightly struggling against SSG and SSB Goku but not fully, In his strongest form He was able to at least survive strikes and attacks from SSB Gogeta, not fight back but able to survive them. Knuckles takes this category (can be debated)