I might be misreading but in case I'm not, you don't have to make the sum of £18,600 (depending on where you work).
If you return to the UK and you get a job that pays £18,600 or higher, you simply have to keep this job for at least 6 months,
then your wife would be able to apply for a spouse visa and join you - so in other words, you don't have to prove you earnt all £18,600,
just that you have a job that ultimately will. If working overseas, you would have to work for 12 months earning the equivalent sum AND have a
confirmed job offer awaiting your return. Hope that helps.Am I now understanding this all correctly?