Try below listed 5 steps to speed up your blog network
- Compress and Resize Images with plugin like WP Smush, Compress or Imsanity.
- Optimizing Script Files with Plugin like ljQuery CDN which will use an external CDN to increase the script’s loading.
- Change Theme which loads faster .
- Do Caching.by installing the plugin Varnish HTTP Purge which with purge cache makes everyone sees the changes applied to blog
- you can blog crawlers by using plugins like Spider Blocker plugin, LinkPrivacy and in advanced cased using .htaccess editing.