Welcome Austin!
A lot of people trash on the stock setup, and say anything but the latest and greatest is trash. I am one to see how far stock will go and then upgrade as needed.
The 4200 nimh batteries will give you enough wheel speed and run time to make progress on a trail, but doesn't have the the energy density of a lipo pack. My old 4200 nimh's would get me about as far as my current 2200 lipo packs, just to give you an idea. I also run 3s or 12.4 volts in my stock Honcho without any ill effects. I do run small tires though.
My advise for anyone new to crawling is to run your rig first, then decide on what you need to change.
Btw, I would not be suprised if your nimh packs were dead.
http://www.rccrawler.com/forum/axial-scx10-ii/593648-trail-honcho-trailing.html