Thank you for bringing up the uncomfortable inequity regarding the independent trucker or the small-fleet operator vs the large fleet companies. There is a solution that, while an extra expense, is not prohibitive and is dual-purpose. I present this here because of the effect it would have on Tesla in increasing the sphere of its market.
A backup power system that consists of a Powerpack (or 2-4, depending on the fleet usage) and a generator is the answer. Megapacks needn’t be considered. Its secondary usage is that “dual”: it provides blackout power. Its primary usage is to charge the vehicles. The key is that all reasonably-sized gensets - ie, those bigger than around 10kW - can have affixed to the motor a powerhead - ie, a generator* , that is wired for three-phase.
I know all of this is eminently feasible, as it is exactly what Tesla Power and I worked out for Paxson. What I do not know is the extent to which any industrial / corporate / environmental / small business / etc. incentives exist in any specific location to address any asssitance in the cost of such set ups.
*For most people, “generator” means that thing with a gas/diesel/propane motor with wires and switches coming out of it. In fact, that is two separate items: the power supplier (that motor) and the generator itself, which excludes the motor and is the set of coils etc. affixed to the motor by a shaft or belts. They’re quite separate, and usually built by different companies. In fact, one can take the entire assembly and switch out a single-phase generator for a three-phase one, wired at 207V, 240V, 480V and so forth. In practice….it’s just a bit more complex.