The guy cut him up into a decent amount of pieces, so my question is now: Should I still brine?
There are three different things that often get confused. Whether the carcass is whole or is cut up doesn't matter.
Aging is when you rest the bird until rigor mortis has passed. You can do this dry or wet. The important thing is to keep the bird cool enough so bacteria can't grow.
Brining is generally considered soaking in a salt mixture. The salt in the brining mixture adds some salt flavor but its main purpose is to retain moisture. If you are dry cooking the meat like frying, grilling, or roasting then brining can help. If you are cooking it wet like baking, crock pot, or pressure cooker then you don't need the extra moisture.
Marinading is when you soak the solution in an acid solution, usually vinegar or wine but it can be other things. The acid breaks down the tissue and reduces toughness. How strong the marinade is and how long you marinade it determines how much tissue breaks down. If it is too long, especially on young birds, it can get mushy. Marinading is very useful on older birds, less useful on young birds.
Some people add different flavors at any of these stages or may combine any two or all three of these. Adding different flavors don't necessary fit in any of these categories, it's just adding flavors. There can be a lot of personal preference in that.
I age mine. I do not brine because I cook mine with a moister method, usually baking but occasionally a crock pot. I seldom marinade, depends on the age and how I cook them. I add flavors when I cook them, not before.
I don't know why you are brining to start with. Did you read on here that you have to brine so you think you have to? I don't brine so I don't feel that you have to. But depending on how you cook them it might be a good idea.