This doesn't appear to be a re-usable task, this is a very specific procedure that belongs to one particular test.  So if this is the only use for this function (I think it is), then it should be moved to `katello.tests.systems`.

And also if that's the case, it doesn't need to use `throw+`, it can use `assert/is`.

On the other hand, if you want to make this re-usable, i suggest the following:  make it take data like this:

```clj
[[#(add "mysys") inc]
  #(delete "mysys") dec]
 [#(multi-delete my-system-names) #(- % (count my-system-names))]]
```
So it would just execute the first function in each row, and then pass the previous system count through the 2nd function, and assert than the current system count is equal to that value.