I didn't mind the fact that he wasn't involved in that bit. He had his own 1 vs 1 fight with Ultron earlier. The beams were enough for me. I'm not sure that a shield throw would've done much damage.
Iron Man also had his one on one
And Thor. And Vision.
In fact, knowing how vibranium work, the beams (energy) should have had less effect on it than a physical blow from the same material.
I don't like how weak was Ultron's vibranium cover treated anyway. I guess they had to de-power it from the comics.
After all, it's just a metal frisbee.
Whedon likes to make fun of Cap, for sure
I don't think that would have meshed with that the way Cap organises the team on the battlefield. He sees his role as containment and protecting the people. He tries to use the more powerful members to go after the head of the snake.
As long as they use him like that in the MCU (as much as it makes sense with his ideals) the GA will see him like a small fry compared to the "power guys", escorting civilians the same way the regulars (Clint, Natasha) were doing.
If anything, he knows the strengths and weaknesses of his team and knows where his place is in the battleplan.
It would be ok if he went: "Heavy hitters, deal with Ultron, we will help elsewhere". For me, it felt like: "Oh, they are doing whatever they want because the are flippin' powerful and I'm a small fry. Well, the weak ones will do the chores meanwhile".
By keeping Cap clueless most of the time (Maria Hill telling the technicalities of the twins' powers to Steve then dumbing it down for him to understand- was painful to watch) and the key plans super-tech-based, the main lead was truly Iron Man's, once again (at least in the final battle).
In the comics Cap gets intel from the tech-savvy guys and assimilate it. In the film he is directly left out.
I'm getting a sour taste about the film and I left it happy, dammit!

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