Batman's durability was never in question. It was about how much beating a guy can take and still move forward. Dude! Him being durable is a given with all the armour, he has on him. Jason doesn't have that kind tech. His tech are low grade and he has a couple of magic swords. He can't run through bazooka or get his body frozen and make it back like nothing .
See, there are two kids. One kid is well built and very strong, he gets hit with large forces he can handle and he hits back. Then there is the second kid. He isn't well built nor strong. yet, even after he gets beat up by large forces
he cannot handle, he crawls up. Who is more apt at taking a beating? First kid or second kid. I would say second kid.it's like this, steve rogers (before the experiment) can handle a beating much better than bucky barnes.