Well, if you distrust integral strikers then you really narrow your selection of boxlocks as the Winchester 21, Parker & Fox guns as well as the majority of British built A&D guns have integral strikers. I'm sure some have broken but I don't think it's all that common & at least one maker (Fox I think) advertised that the integral striker was the better & less prone to failure system.
Disc set strikers have issues also as in my (limited) experience the discs can be very difficult to remove even if you have a correctly fitting disc removal tool & a heavy vise to hold the action. Certainly something I wouldn't attempt to do in the field. I will agree that it is usually easier & cheaper to replace than a a striker integral with the hammer if it does happen.
The best insurance is to travel with a spare gun. Like a jack & a tire repair kit or spare tire, if you have it along you rarely need it.
