This is going to be a slow process. Before each page removed it is set to private. This essentially removes it from the site.
Essentially you've now created 20 crawl errors on your GWT profile, which is not going to help you. There's a much quicker and beneficial way of dealing with it. The best practice would be to 301 these 20 pages to the next best relevant article or if that's not possible, to add a 410 status to these 20 urls using htaccess.
Have you got any pages that you'd consider "thin content" - e.g. just a few sentences or a paragraph with "blow your own trumpet" stuff or too much boilerplate content?
Have you used any product descriptions that you've borrowed from manufacturers or other sources?
Content consolidation on WP is a relatively easy task. I normally use a plugin called "Redirection 2.3.14" (it's free and I'm not affiliated with it)
Basically, if you've got 5 pages that were built to target "how to choose best red widgets", you'd pick the page with the best content, move all salvageable/useful paragraphs from the remaining 4 pages to the chosen page, then send the 4 pages to 'Trash' and set up redirects so that the 4 bad pages redirect to the one good page.
That way not only you consolidate your quality content, you also reuse any potential 'link juice' that the deleted pages used to have.
Also make sure there's only one url to each page. I still keep seeing WP installations with 4 different ways of accessing the content:
http//www.example.com/red-widgets/
http//example.com/red-widgets/
http//www.example.com/p=123
http//example.com/p=123
In this scenario, it's no longer 80 pages and 200 posts but 320 pages and 800 posts. And then add wrongly formatted tag and category archives to the mix and you've got one big nightmare of a site.