A Better Heuristic for Excavator Loading Truck

Currently-- (1) An empty Truck approaches an Excavator. Excavator may or may not have a filled bucket;
(2) Excavator digs a bucket worth of material at its place or it places a bucket quantity of waiting material in Truck;
(3) These actions essentially creates a temporary mating of Excavator and Truck;
(4) Truck waits and the Excavator digs another bucket worth of material at its place. Excavator appears only concerned with is its priority material or whatever is at its place;
(5) If the material is the same as the last bucket, Truck dutifully accepts the material. However, if Excavator loads a different type of material, Truck cannot take it. Truck waits a few seconds and then departs with whatever (small) load it collected from Excavator. Sometimes Truck's load is only a single bucket of material.
Recommendation: once Excavator loads a material in Truck, Truck gets a local *partnership* with the local Excavator(s). Excavator will attempt to dig same material, or ... (out of space)

I think they do get a partnership of sorts. An excavator can have 2 trucks following it, and the excavator is smart enough to switch trucks if it scoops up different material. But I agree that they are not overly smart in how they do it.

More importantly, the excavator should load exactly the needed volume in bucket in order to fill truck, no "here is half a bucket remaining". Trucks and excavators are designed to be matched at about the 3 scoops to a truck which IRL has maximized efficiency. In game, excavators and large trucks also match this and work very well.