Recruits

Solace is roughly the same age as Shining Armour so my headcannon is that they joined the Royal Equestrian Military at the same time. So naturally progressed into me thinking of what they would be like. They'd be good friends, but rivals as well. Solace would nickname Shining Armour "Sparkles" because at first he couldn't remember his name but knew it had to do something with shining or sparkling. Shining would call him "Sunny" in return. As recruits they'd see each other around and compete against each other. After graduating and becoming Captains (Shining of Canterlot Guard, while Solace went out in the field and ended up in the borders of Equestria near the Frozen North); their friendship continued.