@RobZilla:
All his attacks are pretty simple though.
Hit people with barriers or slight variations there of.
Barrier Crash and Barrier Bulls definitely seemed like more potent attacks.
Both of the times that Barto has enclosed people with his barrier have been in pretty specific circumstances though.
He flattened the noble while he scolded him, and contained Gladius' rupturing ability.
As such, I don't think we can point to these incidents when coming to the conclusion that barrier enclosure is a tactic that Barto regularly uses in battle.
I think what we can infer from all the times we've seen Bartolomeo fight is that he is a cocky chicken.
In the arena, when Dellinger was attacking, and all of the Gladius fight to this point, all we saw him do was hide behind the barrier, at times acting smug. Bartolomeo is hard to hit, and if someone hits it with their body, it hurts them (see when Hack attacked him). This was the first time we've seen Bartolomeo actually let himself in danger, and actually land a physical blow. Look at last chapter, where he was at first refusing to let Cabbage in because because of his and Robins safety (I know it was mostly a gag, but it still has some meaning in it).
I feel this is a chapter of people having realizations about themselves. Ussop realized he can no longer hide behind other and be a coward all the time, which can lead to bad things. With this he should slowly get better in that aspect. Here, I think Bartolomeo realized that he as well has been a coward. He idolizes the strawhats, and loves them, but unlike the others running into the danger, he's like Ussop, who hides behind something. After having to protect someone he idolizes, he admitted he's weak, and needs to improve. I think he did that not because it's part of his arsenal, but he actually physically attacked someone for the first time with all his might. I think him taking down Gladius and taking damage will make him improve, and later on will have a more interesting variety of attacks.
Gladius might also be a bit more prone to getting hurt easily, as he probably takes people out before they can touch him, so he most likely never got better defensively. Also, going with the whole crew aging in luxury, he's probably gotten soft over the years like many of the others.