modding hearthguard box

[cranc]

I'm building my fyreslayer army up and just received a free box of hearthguard (last one i ordered was a dud mold but I can definitely get 5 guys out of it) and want to mod them in such away that I can use them both as berserkers and aurics in games.

I'm new to the game and am yet to play competitively though wish to do so in the future, but am not sure on the rules for modding units to make them a hybrid of 2 units to be taken as either or. I had a few ideas which I will list but don't want to start hacking the models up if the end result will be poor so would really like input from anyone who has tried similar things before, how it went, and any general advice or pictures of the outcome.

My ideas:

use thin wire in the axe shaft with a hole in the varying heads (possibly with a tiny magnet at the end if I can find one small enough) so I can swap them as a pin mechanism

assemble as aurics then attach the chains somewhere on the weapon heads or to the small blade on the bottom of the shaft

assemble as berserkers with chains then attach the auric weapon head to the other end of the shaft (darth maul style)

 

The first option has potential practicality issues and will be the most time consuming to pull off if possible, the other two are considerable but my main worry is the weapons looking too clunky and big  or not porperly representing the weapons that are actually being used

 

Again, any advice or input is greatly appreciated