Ok so, this is kind of interesting. I think it kind of conflicts with traditional Steampunk, because steampunk is sort of gothic and high class with technology, so when mixing that with Explorer, you're kind of forced to either "kill" the high class and gothic part into your clothing, or embrace it.
And it seems that you've decided to not really use that in your designs. Another thing I'd like to point out, is what Steampunk can be. If you really think about it, its kind of this style of early industrialization, the days when people walked around with canes and those one eyed classes (which interestingly, Steampunk has its own version called Monogoggles).
So when looking at your designs, I am kind of lacking both aspects of what steampunk is. But I am also lacking the traditional sense of exploration as well. If I go from left to right, the first two don't really imply exploration, and the last one seems like a mage almost.
What I would do here, is, I would do some studies of both regular explorers, the guys with the round hats, rough boots, sometimes gloves, thin shirts with lots of accessories stuck on their belts and backpacks, holding a sword (to cut down leaves) or perhaps a map, and then I would study the gothic style properly, so I could incorporate that into the exploration thing. After, I would attempt to give them some augmentation in the form of technology, and look for some old, early industrial things for that part.
Sorry if this seems like much. It is just that, there isn't too much that screams exploration here, or gothic, and if you could look up some more reference, I'm sure you'd do well!
Anyway, really appreciate the effort put into these! Keep this up! 
