I think including BOTH versions of King Bradley makes this nearly impossible for the Elric Brothers to take down on their own. In general 03 Bradley is one of the strongest/deadliest characters on his own, let alone with a whole team!

If it was only 09 Pride, 03 Wrath, and 09 Bradley they might have a shot...

Having BOTH Bradleys-- even just 09-- is rather overpowered, so they would win

Removing 03 Bradley of the equation, CoS Alphonse was able to raise full armies of armour to fight for him, so if he's paired with Edward, I don't think it's completely hopeless, as long as it's not following 03 rules of "must have the homunculus' remains to kill them".

It's definitely a really lopsided battle though regardless lol