I see we've got varied opinions here, and neither is necessarily "wrong"...
The problem with short trips is that as a "general" rule, it takes a 20 minute drive or more to get the systems up to temp & burn off the moisture that results each time you fire it up cold (it's always producing moisture, but once warm it dissipates immediately).
Figuring a way to vary the use between vehicles so each gets some 'longer" trips on a regular basis is the most practical solution I've seen, Like when "Mom's" car would be used for the "Sunday Drives" so it would get a chance to stretch it's legs regularly...
The worst example of NOT doing this I've seen is on motorcycles that don't get driven in the winter. Some owners would "warm up" their bikes in the garage instead of winterizing them by draining the carburetors. By spring there were major deposits of tan sludge from oil mixed with water in the engine, you'll see the same on the oil fill cap of a car that seldom goes anywhere - especially in the winter.
Short trips are "severe duty" use for a vehicle, & I'm not sure that idle time to try to get it up to temp would be worthwhile in most cases for the reasons stated earlier.
My vote is toward varied use over trying to achieve a "full heat cycle" by excessive idling each time you drive....