So that's 19 vessels 6 of which are active - we seem to spend a lot of time in refit and training TBH - and 2 of our main surface fleet laid up
For decades the RN has planned on 3 escorts to support a task line, i.e. one on patrol, one in refit, one in workup. Which would be 6 from 18. So congratulations, you've just described the RN's tasking cycle. You could probably get a job with the Telegraph...
At least 1 of the T45 is acting as a training ship before going into refit so it's actually helping relieve the manpower issues. But you don't need to know that for the Telegraph job.