from experience multiple truck users ie anything above 5 units prefer same engineer to attend their site. you get to know each other and can talk to each other. also you get to know the trucks , which operators look after the kit and which are rough. some of my operators will give such a good description of faults that you can be thinking about it all the way to site and cure it in a fraction of the time. on the other hand you get the guys who turn and botch up the job knowing that it won,t be them who has fix the thing properly. just stick some rags under the valve chest is a favourite 2-3 weeks later it drips again and someone else gets the job.

when you cover an area as big as mine you have to build good relationships ,i work for a main dealer and competion from the little guy at the end of the road is always a threat.