Position: Team Lead
Team Leads at Target are pretty much self-explanatory; they lead the team (gee, Gina, thanks for that really thorough explanation). They have a managerial position and set goals for the team, make sure that everything is flowing smoothly, and resolve issues on the floor while also doing basic customer service work (or as we call it at Target, "vibing"). Steve, being a military leader and kind soul, would rock this job. He'd make the best motivating huddle (or team meeting) speeches, he'd lay out a great grid to make sure the whole store is covered, and he'd be great at resolving conflicts - because he remembers what it's like to be the little guy getting the short end of the stick. He unfortunately has to trade in his patriotic outfit for more khaki though (but he gets to keep the red).
Position: Electronics Team Member
Tony Stark would clearly work in the Electronics department. These team members are smart, snazzy, and know their products like the back of their hand. Tony would be a great driver of sales, although his snarky attitude might aggravate a few people. But given his experience at Stark Enterprises, Tony knows what he's doing (though he's far more likely to sell his own products - and try and make his own in the backroom), making him overqualified for the job and he knows it and uses it against people (let's for the premise of this fannish idea balloon assume there's a good reason why a bunch of superheroes are working in an American retail store. Use your imagination). However, it can't be denied that the attachment numbers and sales for the department skyrocket with him around.
Position: Softlines, specifically Infant/Toddler, or Baby Hardlines
Look, I had this image in my head of Thor folding baby clothes in his giant Asgardian hands and it was way to cute for me to think beyond it. Also, people who work in Baby Hardlines often also serve as the operator for phone calls and it fills me with joy to think of Thor answering the phone, "GOOD MORROW AND THANK YOU FOR THINE CALL TO TARGET. HOW MAYEST I HELP YOU ON YOUR SOJOURN FOR PURCHASING GOODS?" Or something along those lines.
Position: AP (Assets Protection)
Initially I thought of Natasha as being a hardlines team member, seeing her working in the sporting goods area of the store and making the most she could out of the knives in the camping section. However, I decided that she'd more likely join up with a defensive side and use her skills in persuasion, observation, and action for good and join asset protection, or the police force within Target that works to prevent theft. I also have a really hard time picturing her in red and khaki, so the black security uniform meshes better.
Position: Backroom Team Member
Backroom Team Members are pretty great - you may not see them much, but without them, you'd be screwed. They put together pulls, or carts of items that need to go out on the floor, so guests can get what they need. They do their best to work around items that are sold out and to follow sales projections. They also get to use machines called the Wave, which are a kind of crane-like vehicle that allows them reach higher shelves to pull items from. I can totally see Clint going up in one of these and watching the backroom from above, providing a vital backbone for the whole endeavor.
Position: Market Team Member
It's probably because he turns green, but I instinctively put Bruce in the market or grocery part of the store (Jolly Green Giant reference, I'm so sorry). Also he seems like he'd be the kind of guy to really be interested in nutrition and agriculture and the science of how to improve the food-growing industry. He's probably actually got brilliant ideas that would solve the issues of GMOs and make produce healthier and cheaper. Tony Stark knows this and keeps trying to trick him into showing everyone why he should actually be working in the corporate level, enacting his ideas. However, every once in a while he loses it when a guest is upset that the store is out of eggs again and breaks the cereal aisle.
The last place Loki should actually be is in a space interacting with human customers, but he also needs to be in a place that Thor can keep an eye on him. Thus, the sales floor. Also because of those ads run for Thor: The Dark World, the idea of Loki working in the toy department is adorable and wicked. I suspect it would end with him having giant Nerf gun fights with kids and getting told by those working in Guest Services that if they have to repackage one more item because he messed with it, they're going to smack him. Natasha suspects he's also doing something fraudulent, but she can't prove it. And for some reason, he's actually being kind of nice to people and it makes every one nervous, because he's actually following Thor's "no killing" edict and it's great for business but nerve-racking for everyone on the team. Also no one's certain how he passed the criminal background check after New York (then again, Natasha isn't sure how she did either).
Nick Fury is the leader of them all, the over-arching store manager, or store team lead. Without him, there would be no store. His praise is the mightiest of them all and, while people may doubt his efforts, his store always pulls through to be the most amazing.
Phil Coulson/Son of Coul
Phil Coulson is a man of mystery. So is the position of instocks. It's a very important position - keeping track of what items are out of stock, working to see what needs replenished, seeing what sells fastest, and providing feedback about items are constantly out of stock. However, no one in my store really seems to know exactly how the whole thing works - even those who do this job. Thus, the man who survived having a glowy alien spear thrust through his chest gets the all-important yet not quite explainable job of instocks.
Darcy Lewis/Just Darcy
Oh, I remember those first few days of work. That feeling of terror as you stepped onto the sales floor and saw just how hectic and crazy things were. How much responsibility was placed upon you and how much there was to remember. How cash registers are surprisingly complicated when you put a whole keyboard on them. How many damn acronyms are used. While things may be overwhelming and strange, at least Darcy is finally out of her unpaid internship.
So there you go. The Avengers at Target. It's nutty, but it makes my job sound pretty awesome.