Okay, so I'm trying to figure this one out. At 12th level, a Shield Champion Brawler can do shield damage, or his unarmed strike damage, when attacking with his shield, whichever is greater.
Reading on Shield spikes, it says it makes the shield do damage as if it was one size category larger. So would this allow a Shield Champion to do Large-sized unarmed damage with his shield, or would it be normal Unarmed Strike damage vs. Large Shield damage?