I would suggest that you only need one employee - an in-house editor.

Most writers dislike being edited, it is only natural.

But almost all of them need it.

Even novelists have editors, and in this case the work is effectively commercial.

Hacks have to live with having their purple prose edited, and rightly so.

When I was an editor I would "improve" copy mercilessly, but I always gave the writer a proof so they could raise any issues before publication - I certainly didn't want to misrepresent them, but quality control was vital, a consistent house style was required, and in a print publication there was always the issue of physical space (still a concern on a website, though less so).

The editor takes guidance from the proprietor (in this case you) and deals with the contributors.
S/he needs to be both sensitive and ruthless, understand that the publication as a whole is more
important than any individual piece, and must be able to write extremely well.

Any contributor who does not accept editing is not worth having.

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Hmmm...an editor is a good idea. Something to ponder.

Just because they are in-house that doesn't necessarily mean their writing will get any better. You might be able to keep a closer eye on them but they are still the ones putting words on the page. My thought is, if they were just "okay" at the beginning, why not go find a freelance writer that is great from the get-go. You don't have to settle for okay! When you find someone that loves to write no matter what they are writing about chances are they'll never come back to you with boring or generic fluff content.

And an editor couldn't hurt, but they still need something to work with.

an editor couldn't hurt, but they still need something to work with

The point here is that if there is nothing else to work with then the editor writes it.

That is part of the job description.

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You get what you pay for.

I actually pay more than what most of the writing services pay their writers, but that doesn't seem to help.

And I've run into lots of writers who love to write. That doesn't mean they're any good at it.

Looks like I'm a little late to this thread, but for what it's worth, here's my 2 cents.

I run and manage writers for a living, and just like in any job, passion for the task waxes and wanes. An in-house editor is a BRILLIANT idea, one that I wish most clients would take to heart. Depending on the volume of content that you produce though, you may need more than one.

However, if your contractors writing is becoming dull and generic, it is likely because they are struggling to find new things to say about what you are hiring them to write. No matter what the subject is, unless you are asking them to write whatever they want, their content will become stale.

The key to keeping a writer invigorated and passionate is to give them some new subject to dive into. If they are in-house writers, maybe incentivize them for articles and posts which go viral. Help them with research by giving them new topic ideas that they haven't considered because they've gotten into a "comfortable rut".

Bottom line - if you want your contractors to stay engaged, you have to engage them. If their writing is dull, it's because they are bored. Either get new, fresh writers, or get them fresh topics to write about.