Instead of making individual chapters on each of them and their relationships with each other I'm gonna change things up and look at all of them
All 3
These 3 also have just much of a brotherly relationship with each other as much as Sonic dose with Tails. They all don't get along all the time but all have respect for each other. Silver is also usually the one who keeps Sonic and Shadow from arguing
Sonic and Shadow
Their relationship goes way back to the days of Sonic Adventure 2. At first Sonic saw him as just another copy cat of him plain and simple but he learns to respect Shadow as a hero. Nowadays they tend to annoy each other but make quite the team whenever their together on the battlefield. They also have a stron respect for each other
Sonic and Silver
Their not the type of guys to annoy each other but Silver dose wish Sonic was more patient while Sonic wouldn't mind if Silver wasn't so naive. But their good friends none the less
Shadow and Silver
While Shadow doesn't find Silver as "annoying" as Sonic he dose wish Silver wasn't so naive like Sonic dose. Silver also wishes Shadow wasn't so grumpy all the time and tries to get him to smile every once in a while... Silver fails obviously but he doesn't care