I suspect the difference is that NJS/Cobham have a handle on how to maintain those airframes, which bits break regularly, have the process for changing an engine down pat (albeit without using QC engines), it will very much depend on who maintains these things, but they aren't a 737, don't have the issues a 737 has and isn't as reliable as a 737, so it will require a mindset change.
The saving grace will be, I assume, that these things will sit around during the day and not fly, so the engineers will have plenty of time to work on them, assuming that they actually employ engineers during the day and not rely on the MEL and good luck to get by.