A good bit to know is the power/energy requirements for vehicles is logarithmic. Large vehicles need less energy per unit weight than smaller ones.

A motorcycle might have 300hp per ton. Passenger car 100hp/ton. Train maybe 20hp/ton. South Dakota-class battleship is 3hp/ton.

So yeah size isn't an impediment to electrification.

Some mines are lucky in that trucks deliver payload downhill, making it attractive to charge batteries regeneratively for the empty drive back up. Where that is not the case, electric driving is not attractive at all. Conveyors and cable cars are much easier to electrify, if applicable.

Oh good, I'm glad you've got expert knowledge in the domain. I work on software that manages vehicles in mines.