Multiple vehicles in warehouse has no effect

Reading from the guide published on Steam:

How can I increase the number of delivery locations my Logistics Manager can deliver to?
A couple factors increase your delivery locations.

Type of vehicle. A small vehicle can deliver fewer locations. The freight truck can deliver to the most locations (up to 4 locations each).
Logistics Manager skill level. The more you train your LM skill level, the more locations you can deliver to
    If the Logistics Manager is under 25% skill, a freight truck will service 4 locations.
    Under 50%, it can service 5 locations.
    Under 75%, it can service 6 locations
    Under 100%, it can service 7 locations
    At 100%, it can service 8 locations.
And of course, if your warehouse has two vehicle slots, you can put two vehicles in there and double your locations.

However, I currently have a >= 50%,<75% Logistics Manager assigned to a warehouse with 2 vehicles & 2 Delivery Drivers, and I can only serve 6 locations.
Hence, it does not seem the number of locations able to be served scales with the number of vehicles assigned to a warehouse. How do I take advantage of multiple vehicles assigned to a warehouse?

I found a previous bug fixed in EA 0.1 which seems to have fixed a strange behaviour, but maybe what has been fixed were meant to provide this feature?.

It sounds like you have two vans in the warehouse. If so, that is correct. You need a freight truck to get the maximum number of locations.

You are right: the 2 vehicles I own are vans.

Is there anything written about truck types regarding the number of locations being handled, on top of the Logistics Manager’s level?

A car can do 1, a van/small truck can do 2, and a freight truck can do 4. Then if your Logistics Manager is at 100%, it will double that number

Thanks for that!
It would be nice to find that as part of the in-game documentation… or maybe is it already there and I failed to find it?

Does the Logistics Manager, based on its skill, applies a multiplier or just adds 1 location served for each stage described in the aforementioned documentation?

You right, there are some areas in-game that could use a lot more explanation!

Exactly. At 100% skill it doubles the vehicle capacity of whatever is there. So a freight truck goes from 4 to 8. A van goes from 2 to 4

OK, so based on the documentation I initially quoted, I will try to sum what needs to be known up.

Vehicles type capacity:

Vehicle type Capacity
Car 1
Van 2
Truck 4

Logistics Manager multiplier per vehicle:

Logistics Manager skill S Multiplier
0 % ≤ S < 25 % 100 %
25 % ≤ S < 50 % 125 %
50 % ≤ S < 75 % 150 %
75 % ≤ S < 100 % 175 %
100 % 200 %

This would translate as the following capacities:

LM skill S / Vehicle type Car Van Truck
0 % ≤ S < 25% 1 2 4
25 % ≤ S < 50 % 1,25 2,5 5
50 % ≤ S < 75 % 1,5 3 6
75 % ≤ S < 100 % 1,75 3,5 7
100 % 2 4 8

This table would match the documentation example for a warehouse containing a single truck.
This matches my case too, with 2 vans and a Logistics Manager with 50% <= skill < 75%: 6 locations served.
… but those cases are simple, with round values.

I wonder how values are rounded when required: is it a mathematical, high-bound or low-bound round?

However, a driver must have a minimum skill to drive a truck.

Correct, the driver must have 50% skill to drive the freight truck.