I'm told that it's been done although I'm not sure by whom, most likely someone in the UK community (or someone at the playtest weekend last november)
the basic idea is that the flame cannon crew already have very miner-looking helmets and one is toting a big shovel, my idea would be to snip off the tips of the artillery kit they're carrying and add some GS-sculpted mattock/pick heads, the rangers who are waving their crossbows around need very slight modification to turn the crossbow into a pick, and a miner helmet sculpting on
I'm thinking 4-5 a base with plenty of rocks and scenery will be enough to work well as a scouting force tunneling up behind enemy lines
