If you have more than one vehicle that you need to charge, you need more than one outlet. Worse, you cannot just get connect all of them to one outlet through daisy chained extension cords: you need separate 120V circuit for each vehicle. Even if you are lucky enough to have multiple outlets around where you park your fleet, these will likely all be on the same circuit.
This problem is of course solvable, you need to build a charging station. The point is that you need more than "just an outlet".
Nope. You only need a 15A branch per vehicle. You can install a 30A branch, too, if you like, and two poles of those are enough for 4 vehicles. For slow charging purposes, 120V exterior outlets are more than good enough and have commonly been used for government electric vehicles for decades.
Slow charging may not be fast enough. Around here, I'll sometimes see them making (mostly) parcel deliverys as late as 9PM, and then they're out in the morning at 4 or 5AM.
This problem is of course solvable, you need to build a charging station. The point is that you need more than "just an outlet".