It is necessary to monitor the workload of the stations. At stations with many resources, additional transport should be sent.
There are about 10 trucks needed for grain and livestock — I would first buy half: 5 for grain and 5 for livestock. If after some time the station is still overloaded, then buy 5 more for each.
If there are too many vehicles at a station, it’s a good idea to build additional stations on the sides so that the trucks don’t line up in a long queue.