When I was in England most of my work was very compact, having been built up over a number of years.
Part of my run was two neighbouring villages, each of which I could park up and walk round each day for a month without moving the van.
I remember losing a handful of non-payers, and another to an undercutter in one of the villages. The rest were model customers, I maybe had one 'not today' once a year, and was happy to roll with that. The run was a dream, no hassles whatsoever.
That said, there were also other windys around, but we always had a chat and there was no rivalry at all whenever we saw each other about, apart from one guy with a smart Transit sized van, all whistles, bells and hoses, who turned his nose up at us lowly tradders!
No, it never worried me that I would lose any of my compact work. I never lost any that made any difference to me.
Now I am in Ireland I have some compact work which has taken 2 and a half years to build. There have been messers/non payers who have been dropped. I still do their neighbours and haven't had any difficulty keeping them. In my view, if you do a good job, are reliable, honest and offer good value for money, most customers will repay you with their loyalty.
John