Just watched it again, if there is any one soul here who loves the lore and the world of steampunk Arcanum that has yet to watch Steamboy 2004 (anime movie) I find it my obligation to point you to the enlightenment. In the movie when I first saw machined platemail wearing troops I was awed, then there came flying steam suit troops and submarine troops in trash cans (no better way of describing them) and it follows up with magnificent steampunk wonders. I find it sad that movie was not much popular, apparently those with same taste of ours are few in numbers; yet it is a relief that such fantastic works are published nonetheless.
On the topic of things in anime that remind us of Arcanum, the robot soldiers from Miyazaki's "Laputa: Castle in the Sky" reminded me of automatons.
Ghibli movies are often very steampunky in general. He always had a knack for flying machines, and those tanks in NausicaƤ were just great.
Take a look at the anime "last exile". They have classical warship battles with steam powered airships. It's absolutely beautiful.