R1- I think Matt is the better fighter skill-wise, and has much greater durability. Oliver is stronger, but I believe Matt's advantages give him the edge. Daisy doesn't have the degree of skill Sara has shown. She's impressive, and can hold her own against SHIELD agents very well, but Sara seems much more skilled and faster, it's debatable who is stronger as neither really have top tier striking feats, but Sara's blows seem to send people falling back farther, and typically in less moves than Daisy.
R2- Probably the closest round for Oliver imo, but Daredevil has shown great proficiency handling ninjas trained with bladed weaponry, even when he was essentially blind. I don't think Oliver can beat him here, but he has a better shot at doing more damage. Conversely, this is Daisy's worst round. She's shown no skill with any melee weapon, whereas Sara is highly proficient with the bo-staff.
R3- Matt's shown he can react to arrows easily, so that shouldn't be an issue for him. He can clear the distance between himself and Oliver, and it essentially becomes a repeat of R1 or R2. Definitely Daisy's best chance here. She's demonstrated a solid grasp of firearms, and the willingness to shoot to kill. I think Sara is savvy enough to evade the gunfire, but it's a pretty great equalizer in Daisy's favor. I think this is where Sara being faster is instrumental as she can react a lot quicker, and she's a smart enough fighter to know how to disarm an opponent.
However Avengers should win imo, as much as I loath to admit it
Same boat. I'm not a fan of the ANAD Avengers, but if Foster was capable of stalemating Odin (with no hax other than PIS in place) I think they should win. If it's Foster as she's been written by everyone other than Aaron, then I think the Squadron should win.
I'm also unsure if the new Iron Man armour is stronger than the Extremis. From all accounts it should be, it looks as versatile as the EndoSym but it doesn't seem nearly as durable.